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Chapter 6 – Output Report

6.1 – General Information

There are two types of output reports. One is an output report which gives an overview of decision-making and management information. The other is output detail which provides output in the form of tables, graphs, charts and exports. After you run the simulation, both types of output reports are available from the View menu.

View menu of ProcessModel simulation software

6.2 – Analyzing Output Report

ProcessModel simplifies the process of generating and analyzing the output data as well as increases performance on the generation and analysis side. Data is gathered from all scenarios and replications in a structured format, ready for easy analysis. The Output Report provides information regarding activities, resources, entities, variables, total process cost, burdened cost per entity, resource costs, manufacture or service time, the amount of process time that provides value to the customer and custom statistics of your choice. This information is provided in tabular form with the ability to pull information from many model experiments to compare results.

See Output Summary results of a ProcessModel simulation

1. When the simulation is complete (or you have ended it manually), choose No when you see the following dialog.

Simulation complete prompt for ProcessModel simulation software

Important information to be aware of If you end the simulation from the Simulation menu while the simulation is still running, ProcessModel will prompt you for verification before displaying the above dialog.

2. You will now be in the model build area. From the toolbar click the output report button Output report button / icon or goto the view menu and select Output Report. The following dialog box will appear.

Output Report of ProcessModel

6.2.1 – Scenarios & Replications

After running multiple replications (a sample from a different time of the same model) or multiple scenarios (an experiment with different input parameters), the Output Report will allow the selection of statistics from each category as shown below.

Output Report with scenarios and replications

Click on the names in the tree diagram on the left to display summary information on a single run, multiple scenarios and / or multiple replications.

Important information to be aware of The information is only displayed when the simulation is done with scenarios and / or replications.

Clicking on the tree diagram will show or hide information based on your level of selection. When selecting a scenario containing replications, you will see average values of all replications for that scenario. When selecting a replication, you will see only data for that replication. For information on setting up multiple replications, see Chapter 5, Section 5.1.1, Run Tab.

6.2.2 – General Report

The general report contains the valuable decision making information regarding activities, resources, entities and variables. It provides information that is vital to the modeler to assure complete understanding of the operation of the system under study. This detailed information allows an in depth view of every activity, storage and resource.

1. Click on the General Report from the tree and then the General Info tab, to see the general information on the simulated model.

General tab in output report of ProcessModel

Date: The date model was simulated.

Output from: Output file path.

Replication: Number of replications performed.

Scenario: Scenario name, if any.

Simulation Time: Total simulation time.

Time: Time the report was generated.

Important information to be aware of If you have only scenarios in your model you will need to click the name of the scenario to see the general report.

Important information to be aware of If you have replications in your model clicking the general report will show you the averaged report, clicking on any replication number will give you report on that particular replication.

Important information to be aware of If you have scenarios and replications in your model clicking the scenario name will show you the averaged report, clicking on any replication number will give you report on that particular replication.

2. Click on the Activities tab on the right, while on the General Report in the tree to see the activity information.

Activities tab in output report of ProcessModel

Activity Name: Names of all the activities that have been added to the model with statistics enabled.

Scheduled Hours: The total number of hours the activity was scheduled to be available, as the result of any shift file it uses, defined in the properties dialog.

Capacity: Capacity of the activity, defined in the properties dialog.

Total Entries: The total number of entities that entered the activity, not including entities arriving to be attached. Entities arriving that have been previously grouped or have entities attached to them to form a single entity only count as one entry.

Average (Sec/Min/Hrs/Days) Per Entry: Average time an entity spent at the activity, time value is based on what is selected in the Simulation \ Options window. This time may include partial times from the beginning and end of the actual run time.

Average Contents: Average entities in the activity at the same time.

Maximum Contents: The maximum number of entities which occupied the activity at the same time, over the course of the simulation.

Current Contents: The number of entities remaining at the activity when the simulation ended.

% Utilization: The percentage of capacity occupied, on average, during the simulation.

(Cumulative Occupancy Time x 100) / (Capacity x Scheduled Time)

Value Is: Displays if the values are 90%, 95%, 99% Confidence Interval, Average, Min, Max, Skewness or Standard Deviation values.Important information to be aware of The value is only displayed when the simulation is done with replications.

For more information, see Confidence Interval.

3. Click on the Activity by % (Multi Cap) tab on the right, while on the General Report in the tree to see the activity percentage information on multi capacity activities.

Activities by percentage multiple capacity in output report of ProcessModel

Activity Name: Names of all the activities that have been added to the model with statistics enabled and have a capacity of more than 1.

Scheduled Hours: Scheduled hours for the activity, defined in the properties dialog.

% Empty: Percentage time the activity was empty.

% Partially Occupied: The percentage of time the activity had entities but was not filled to capacity.

(100% of time – %Full – %Empty)

% Full: The percentage of time the activity was filled to capacity with entities.

Value Is: Displays if the values are 90%, 95%, 99% Confidence Interval, Average, Min, Max, Skewness or Standard Deviation values.Important information to be aware of The value is only displayed when the simulation is done with replications.

For more information, see Confidence Interval.

4. Click on the Activity by % (Single Cap) tab on the right, while on the General Report in the tree to see the activity percentage information on single capacity activities.

Activities by percentage single capacity in output report of ProcessModel

Activity Name: Names of all the activities that have been added to the model with statistics enabled and have a capacity of 1.

Scheduled Hours: Scheduled hours for the activity, defined in the properties dialog.

% Operation: The percentage of time the activity was actually processing an entity.

% Idle: The percentage of time that no entities were at the activity, but the activity was not down.

% Waiting: The percentage of time the activity was waiting for a resource or another entity in order to begin processing or move to the next activity. Any delays in processing routing Action logic are counted as waiting time.

% Blocked: The percentage of time entities spent waiting for a freed destination. “Blocked” means that an entity cannot move downstream in the model due to insufficient capacity at the next location. The entity has to sit at the current location, after the normal processing time is complete, until there is room available for it to move.

Value Is: Displays if the values are 90%, 95%, 99% Confidence Interval, Average, Min, Max, Skewness or Standard Deviation values.Important information to be aware of The value is only displayed when the simulation is done with replications.

For more information, see Confidence Interval.

5. Click on the Resources tab on the right, while on the General Report in the tree to see the resource information.

Resources tab in output report of ProcessModel

Resource Name: Names of all the resources that have been added to the model.

Units: Number of resources assigned, defined in the properties dialog.

Scheduled Hours: The total number of hours the resource was scheduled to be available, as determined by the assigned shift file, defined in the properties dialog.

Number of Times Used: The total number of times the resource has been acquired to transport or process an entity.

Average (Sec/Min/Hrs/Days) Per Usage: The average time the resource is used by an entity. Time value is based on what is selected in the Simulation \ Options window.

% Util: The percentage of time the resource spent moving or processing an entity.

(100 * (Number of Time Used * Average Minutes Per Usage)) / (Scheduled Hours * 60 min/hr)

Important information to be aware of Resources are reported both by unit and collectively. The collective unit (aggregate) report for a resource totals the first three fields and averages the last two fields discussed above.

Value Is: Displays if the values are 90%, 95%, 99% Confidence Interval, Average, Min, Max, Skewness or Standard Deviation values.Important information to be aware of The value is only displayed when the simulation is done with replications.

 Divide the times used value by the scheduled hours and that will give the average number of entities processed in 1 hour by each resource. If detailed information is needed on hourly times used by a resource, then the Report with Reset statement can be used to generate the hourly data.

For more information, see Confidence Interval.

6. Click on the Resource by % tab on the right, while on the General Report in the tree to see the resource percentage information.

Resource by percentage information tab in output report of ProcessModel

Resource Name: Names of all the resources that have been added to the model.

Scheduled Hours: Total scheduled hours for the resource during simulation, defined in the properties dialog.

% in Use: The percentage of time the resource was being used by entities.

% Idle: The percentage of time the resource was available but not in use.

% Down: The percentage of time the resource was unavailable due to shifts or options selected in the Availability tab for the resource.

Value Is: Displays if the values are 90%, 95%, 99% Confidence Interval, Average, Min, Max, Skewness or Standard Deviation values.Important information to be aware of The value is only displayed when the simulation is done with replications.

For more information, see Confidence Interval.

7. Click on the Entity tab on the right, while on the General Report in the tree to see the entity information.

Entity tab in output report of ProcessModel

Entity Name: Names of all the entities that have been added to the model with statistics enabled.

Qty Processed: The total number of entities processed through the model.

Average Cycle Time: The average time each entity spent in the model.

Cycle Time is the total elapsed time to move a unit of work from the beginning to the end of a physical process. Cycle time includes process time, during which a unit is acted upon to bring it closer to an output, and delay time, during which a unit of work is spent waiting to take the next action.

Average VA Time: Average value added time each entity spent being processed in activities or moved from one activity or storage to the next, does not include time waiting or time at any activity that is declared as a NVA (Non Value Added).

 Activity time begins as soon as an entity enters the capacity of the activity, and ends when the entity leaves the capacity, either by moving to the output queue or to the next location in the model. Value added time is accrued only from a TIME statement in the action logic or from the General tab’s Time field.

Average Cost: The average cost of the entity. This is based on how much work was done on the entity by activities, resources etc that have an associated cost. Important information to be aware of Unused resource cost is not applied to the average cost, to see cost with unused resource cost added, see the Entity Cost in the tree to the left.

Value Is: Displays if the values are 90%, 95%, 99% Confidence Interval, Average, Min, Max, Skewness or Standard Deviation values. Important information to be aware of The value is only displayed when the simulation is done with replications.

Only entities that exit the model have statistics collected for them and reported. If an entity is renamed at some point in the model, the original entity will not report statistics. Only the new name will show stats. Another instance when the entity summary will show 0’s is when one entity is attached to another without detaching them before they exit the model.

For more information, see Confidence Interval.

8. Click on the Variables tab on the right, while on the General Report in the tree to see the variable information.

Variable tab in output report of ProcessModel

Variable Name: Names of all the variables that have been added to the model with statistics enabled.

Total Changes: The total number of times that the value of the given variable changed during the simulation.

Average (Sec/Min/Hrs/Days) Per Change: The average time that a given variable remained at any one value. Time value is based on what is selected in the Simulation \ Options window.

Minimum Value: The lowest value of the variable during the simulation.

Maximum Value: The highest value of the variable during the simulation.

Current Value: The final value of the variable when the simulation ended.

Average Value: The average value of the variable during the simulation. This value is time weighted.

Value Is: Displays if the values are 90%, 95%, 99% Confidence Interval, Average, Min, Max, Skewness or Standard Deviation values. Important information to be aware of The value is only displayed when the simulation is done with replications.

For more information, see Confidence Interval.

9. Click on the Filter tab on the right, while on the General Report in the tree to see the filter options available.

Filter tab in output report of ProcessModel

The filter tab contains subtabs, these subtabs can filter contents of the specific tabs mentioned in the header of the subtab.

Activities: Filter input or output queues, or the activities themselves by checking or unchecking the relevant boxes.

Resources: Filter resources to show or hide resources by checking or unchecking the relevant boxes.

Entities: Filter entities to show or hide entities by checking or unchecking the relevant boxes.

Variables: Filter variables to show or hide variables by checking or unchecking the relevant boxes.

Statistics: Filter 90%, 95%, 99% Confidence Interval, Average, Min, Max, Skewness or Standard Deviation values for all relevant main tabs.Important information to be aware of The value is only displayed when the simulation is done with replications.

For more information, see Confidence Interval.

6.2.3 – Total Cost

Click on the Total Cost in the tree at the left hand side to see the total cost information.

Total cost in the output report of ProcessModel

Name: Not Applicable.

Total Cost: The total cost for running the process for the entire simulation time. Total Cost represents the sum of all the costs to run the process plus the addition of all unused resource costs. Includes sum of;

1. Used / Unused Resource cost.
2. VA, NVA, and BVA costs for each entity.
3. Initial entity cost.
4. Entity waiting cost.

The Output Detail report does not include unused resource cost, and uses an ABC costing method which only includes direct entity costs.

Business Value Added (BVA) activities are required by law, used for necessary audits or needed for subsequent activities but not required by the customer. Business Value added activities do not add value to the product or service from the customer’s perspective. Also called Book Value Added.

For more information, see ProcessModel and Activity-based Costing.

6.2.4 – Entity Cost

Click on the Entity Cost in the tree at the left hand side to see the entity cost information. This uses the ABC costing method. In other words, the reported entity cost is only the direct costs associated with producing that entity.

Entity cost in output report of ProcessModel

Name: All the entities that have been added to the model with statistics enabled.

Average Cost: Average cost of entity. Entity Cost provides you with the cost to produce one entity. Unused resource costs are applied to each entity. This gives you a realistic picture of all costs involved in producing an entity. The cost of unused resources is automatically allocated across entities according to the number of each type of entity that exits the simulation. Important information to be aware of Unused resource cost is not applied to the average cost shown in the Entity tab of the General Report.

6.2.5 – Resource Cost

Click on the Resource Cost in the tree at the left hand side to see the resource cost information.

Resource cost in the output report of ProcessModel

Name: Names of all the resources that have been added to the model.

Cost of Used Resource: Total cost of used resources. If the resource is on break, no cost is charged.

Cost of Unused Resource: Total cost of unused resources. Represents the time you must pay for even though a resource may not be actively working on entities. This table helps you to quantify the resource waste in your process. Important information to be aware of Unused costs are not included in the Output Detail report which uses ABC costing.

6.2.6 – Value Added Time

Click on the Value Added Time in the tree at the left hand side to see the value added time information.

Value added time in output report of ProcessModel

These breakdowns allow you to determine what part of your process provides the values and what part does not. To set an activity to, or see the definition of Non-Value-Added or Book-Value-Added see information under VA Time.

Name: All the entities that have been added to the model with statistics enabled.

Avg. VA Time*: Is based on the time an entity spends being worked on.

Avg BVA Time*: Is based on any time an entity spends being worked on in an activity that is declared BVA, can’t be passed on as a cost to customers (e.g. inspection time).

Avg NVA Time*: Is based on the time an entity spends being idle, waiting for a resource, in a storage, traveling on a route, waiting in an input queue or when it’s held by a Wait Until statement.

Avg Total Cycle Time: Average total cycle time for all entities processed.

Average times are calculated based on all the entities that were completely processed during the simulation.

6.2.7 – Variable Statistics

Click on the Variable Statistics in the tree at the left hand side to see the variable statistics information.

Variable statistics in output report of ProcessModel

Name: All the variables that have been added to the model with statistics enabled.

Avg. Value: The average value of the variable.

Max. Value: The maximum value of the variable.

Std Dev.: The standard deviation of the variable.

6.2.8 – Hot Spot Evaluator

The Hot Spot Evaluator is an output report that identifies what area of your model you need to focus on to see the greatest improvements. All NVA (non value-added) item opportunities are listed from the greatest to the least opportunity. Below the NVA items are the VA (Value adding) item opportunities listed from the greatest to the least. With the Hot Spot evaluator you can see opportunities faster.

1. Click on the Hot Spot Evaluator from the tree and then the Table tab, to see the hotspot evaluator information.

Hot spot evaluator table in output report of ProcessModel

Status: Details if the activity was value added (VA), book value added (BVA) or non-value added (NVA). See more information under VA Time.

Activity Name: All the activities that have been added to the model with statistics enabled.

Entries: Total entities that passed from the activity.

Total VA Min*: Is based on the time an entity has spent in the capacity of the activity, even if an entity is waiting for a resource, since the activity space is being utilized.

Total BVA Min*: Is based on the time an entity has spent in the capacity of the activity that is declared BVA, even if an entity is waiting for a resource, since the activity space is being utilized.

Total NVA Min*: Is based on the time an entity has spent in the input or the output queue of an activity (depends upon an input/output queue cap).

Total Min*: Total time spent by an entity in an activity.

% of Total: 

% of VA: 

% of BVA: 

% of NVA: 

* Totals are based on the total time all entities that have passed through, are currently in the activity, or are in the activity queue.

2. Click on the Chart tab on the right, while on the Hot Spot Evaluator in the tree to see the available charts.

Hot spot evaluator chart in output report of ProcessModel

Save button: Provides the ability to save chart

Copy button: Provides the ability to copy the chart to clipboard as a bitmap, metafile, text or to an office application.

Vertical Grid button: Add or remove vertical grids from the chart.

Horizontal Grid button: Add or remove horizontal grids from the chart.

Legend Box button: Add or remove legends.

Properties button: Provides a host of features to change the chart properties including chart title.

3d/2d button: Toggle between 3d or 2d chart view.

Rotate button: Rotate the chart by changing chart properties.

Zoom button: Zoom into the chart. Press the zoom button and then click and hold on the chart area to which you want to zoom into.

Print Preview button: Displays customizable print preview information.

Print button: Print the chart using the default printer.

Right clicking on any of the chart position displays menu relevant to the specific area of the chart.

Right click on the white space of the chart to;

1. Toolbar: Show / hide the toolbar buttons.

2. Data editor: Show / hide the data editor.

3. Legend box: Show / hide the legend box.

4. Gallery: Change graph type.

5. Color: Change background color.

6. Edit title: Edit chart title.

7. Point Tables: Show / hide points on tables.

8. Font: Change text fonts.

9. Properties: To open the relevant tab in the properties window (see Properties button above).

Right click on any of the chart graphs to;

1. Gallery: Change graph type.

2. Color: Change graph color.

3. Properties: To open the relevant tab in the properties window (see Properties button above).

Right click on any of the text in the chart to;

1. Edit Title: Used to edit specific chart title.

2. Font: Change the specific text fonts.

3. Color: Change the specific text color.

4. Properties: To open the relevant tab in the properties window (see Properties button above).

Right click on legend box in the chart to;

1. Hide: Hide legend box.

2. Autosize: Turn autosize on or off.

3. Font: Change fonts.

4. Fixed / Floating: Change legend box properties to be fixed or floating.

5. Left / Top / Right / Bottom: Move legend box to either of the directions.

Activity names which exceed 92 characters will display a blank chart view as there isn’t room to display the bar chart and the activity name. When viewing the chart, the maximum number of characters you can have in an activity name is 92. Typically the “text” displayed on the activity graphic is the same as the activity “name” except that spaces are replaced by underscores in the Name field of the Properties Dialog Box. However, there may be long text on the graphic, and a shorter, or different name in the Name field. Just click in the Name field and edit the name to bring it within the 92 character limit. If there is need to have that much text shown on the model, consider putting the text in a text box as a note, rather than placing it on the activity itself. All notes can be pulled on a second layer, allowing the ability to show or hide the notes layer as needed.

3. Click on the Filter tab on the right, while on the Hot Spot Evaluator in the tree to see the available filter options.

Hot spot evaluator filter in output report of ProcessModel

Filter input or output queues, or the activities themselves to be used in the chart, by checking or unchecking the relevant boxes.

6.3 – Output Detail Report

The Output Detail report provides information that is vital to the modeler to assure complete understanding of the operation of the system under study. This detail information allows an in depth view of every activity, storage and resource along with access to custom graphs of user defined data. The tree diagram below shows the type of data that can be extracted from the Output Detail reports and graphs

Output detail report graphs

See the results of a ProcessModel simulation

1. When the simulation is complete (or you have ended it manually) choose yes when you see the following dialog.

Simulation complete prompt for ProcessModel simulation software

Important information to be aware of If you end the simulation from the Simulation menu while the simulation is still running, ProcessModel will prompt you for verification before displaying the above dialog.

Important information to be aware of To open Output Detailed Report from ProcessModel main window, click View \ Output Detail.

6.3.1 – Detail Report Window

The Output Detailed Report makes certain assumptions to ease your way into charting from the View menu and the toolbar.

Output detail report toolbar

6.3.2 – File Menu

The File menu allows you to open one or more output databases for review, analysis, and comparison.

You can also export time series data and save reports you generate to a text file. And of course, you can print graphs and reports from the output databases you have opened. Below is a description of each of the menu options under the File menu. Some menu items have a corresponding button on the button bar, and when you move the mouse over the button, a message appears at the bottom of the window indicating what the button does if pressed.

Open Opens a single output database (*.RDB) file.

Open Multiple Open several .RDB files for viewing and comparison (covered in detail in“Multiple Output Files”).

Save As Saves a copy of the report you created to a text or Excel file.

Open Manage Chart Views Allows the setup of multiple presentations (views) of the output information called by separate names.

Save Active Chart View Preserves the currently open reports and graphs so they will open automatically with new data in subsequent runs.

Important information to be aware of Template models transferred to another person will always maintain saved reports.

Save Active Chart View As Preserves the currently open reports and graphs under an new name.

Print Preview Shows what the current graph or report will look like when printed.

Print Prints the current graph or report to your printer.

Print Setup Displays the standard Windows printer setup dialog.

Multiple Output Files

Open Multiple Displays the currently open output database files and allows you to add or remove output databases from the list. These open database files are used in creating graphs and reports in the Output Module.

This is useful for viewing output data for more than one simulation run or from other models for side-by-side comparison. For example, you may have a model which represents the current system of a manufacturing plant. A different model may represent the desired future system for the same manufacturing plant. Opening multiple output files allows you to compare differences in utilization percentages, etc.

Output detail report of ProcessModel - Open multiple windows

Add Displays the file open dialog allowing you to open another output database file.

Remove Removes the highlighted output database file from the results files list.

Remove All Allows you to remove all the output database files from the files list.

Important information to be aware of Note that more than one report or graph may be opened simultaneously. Each report and graph is contained in its own sizable window which allows you to create several reports and graphs for comparison.

When you select Save Active Chart View, a reports and graphs file is created: .RDW where file_name is the filename of the current open output module file. For a detailed explanation of these and other files.If multiple output module files are opened when you use this option, the files needed to generate the reports and graphs that you want to keep will be recorded in a single .RDW file. When opening multiple output module files, only the first file opened will have its associated .RDW file opened, so the first output module file opened determines what reports and graphs to automatically generate.

6.3.3 – View Menu

The View menu allows you to select the way in which output data is displayed.

Output detail report of ProcessModel - View Menu

Below is a description of each of the menu options under the View menu.

General Stats Creates a general summary report. If there is only one scenario and one replication, the report will be generated automatically, otherwise an options dialog appears to allow you to select the replications to be displayed in the report. (See General Statistics Report)

Selected Stats The Selected Stats report allows you to create a replication report with only the specific statistics and elements you want in the report. The Selected Stats report is only available if there are multiple replications. (See Selected Statistics Report.)

State or Utilization Summary In ProcessModel an averaged state summary is produced for multiple replications in which a number of state or utilization graphs is available. (See Utilization Charts & Graphs.)

Time Series The time series option allows you to create plots or histograms from information taken during the simulation. The plot shows the value of the statistic over time. The histogram shows the percentage of time that the statistic’s value was within certain ranges. (See Time Series Plots & Histograms.)

6.3.4 – Options Menu

Output detail report of ProcessModel - Options Menu

Customize Current Window Allows you to alter the type of data displayed in the output report as well as the font used.Displays the options dialog specific to the current report or graph.

Preferences This option allows you to select the decimal precision of the output report. In addition you can select to open the default view have the system prompt you for the view to open.

Customize Current Window

You must have an output report displayed before this option will become available. You can change the text font at any time. However, to change the statistics shown, you must have run your simulation using multiple replications (See Set up Multiple Replications).

Output detail report of ProcessModel -General Report Window

6.3.5 – Viewing Reports

Output detail report of ProcessModel - View Menu

From the View menu you can generate general summary reports, selected statistics reports, state and utilization summaries, and time series plots and histograms.

Note that more than one report or graph may be opened simultaneously. Each report and graph is contained in its own sizable window which allows you to create several reports and graphs for comparison.

6.3.6 – Reports Terminology

The Output Module provides information on activities, resources, arrivals, entities, variables, etc. While some of the statistics reported for these model elements are easily understood, others deserve further explanation.

Activities

The Output Module organizes information for activities, input queues, and output queues. Input and output queues are given the same activity name as their associated activity with the addition of inQ or outQ at the end of the name. (Storage objects are listed under Activities in the output report.)

Scheduled Hours: The total number of hours the activity was scheduled to be available, as the result of any shift file it uses.

Capacity: The capacity defined in the properties dialog.

Total Entries: The total number of entities that entered the activity, not including entities arriving to be attached. Entities arriving that have been previously grouped or have entities attached to them to form a single entity only count as one entry.

Average

Average Contents: The average number of entities in an activity.

Maximum Contents: The maximum number of entities which occupied the activity over the course of the simulation.

Current Contents: The number of entities remaining at the activity when the simulation ended.

% Util: The percentage of capacity occupied, on average, during the simulation. (Cumulative Occupancy Time x 100) / (Capacity x Scheduled Time).

Activity States By Percentage (Multiple Capacity)

For activities, queues, and storages having a capacity greater than one, the following statistics are meaningful.

Scheduled Hours: The total number of hours the activity was scheduled to be available.

% Empty: The percentage of time the activity had no entities

% Partially Occupied: The percentage of time the activity had entities but was not filled to capacity (100% of time – %Full – %Empty).

% Full: The percentage of time the activity was filled to capacity with entities.

Activity States By Percentage (Single Capacity)

Scheduled Hours The total number of hours the activity was scheduled to be available.

% Operation: The percentage of time the activity was actually processing an entity.

% Idle: The percentage of time that no entities were at the activity, but the activity was not down.

% Waiting: The percentage of time the activity was waiting for a resource or another entity in order to begin processing or move to the next activity. Any delays in processing routing Action logic are counted as waiting time.

% Blocked: The percentage of time entities spent waiting for a freed destination.

Resources

Units: The number of units defined in the resource’s properties dialog.

Scheduled Hours: The total number of hours the resource was scheduled to be available, as determined by the assigned shift file.

Number of Times Used: The total number of times the resource has been acquired to transport or process an entity.

Average

Important information to be aware of Resources are reported both by unit and collectively. The collective unit (aggregate) report for a resource totals the first three fields and averages the last two fields discussed above.

Resource States By Percentage

Scheduled Hours: The total number of hours the resource was scheduled to be available.

% In Use: The percentage of time the resource was being used by entities.

% Idle: The percentage of time the resource was available but not in use.

% Down: The percentage of time the resource was unavailable due to shifts or options selected in the Availability tab for the resource.

Entity Activity

Qty Processed: The total number of entities processed through the model. (Same as listed in the scoreboard during the simulation.)

Average Cycle Time: The average time each entity spent in the model. (Same as listed in the scoreboard during the simulation.)

Average VA Time: The average time each entity spent being processed in activities or moved from one activity or storage to the next. (Same as listed in the scoreboard during the simulation.)

Average Cost: The average cost assigned to each entity throughout the model. (Same as listed in the scoreboard during the simulation.) This costing accounts only for direct cost applied to the entities because of time and cost calculations. Unused resource time is not applied to this cost calculation. The Average cost of entities would be the lowest possible cost that the entity could be produced for if the resources were utilized 100% of the time. The cost in the Summary Report accounts for all unused resource time and spreads it across exiting entities.

Variables

Total Changes: The total number of times that the value of the given variable changed during the simulation.

Average

Minimum Value: The lowest value of the variable during the simulation.

Maximum Value: The highest value of the variable during the simulation.

Current Value: The final value of the variable when the simulation ended.

Average Value: The average value of the variable during the simulation. This value is time weighted.

6.3.7 – General Statistics Report

General Stats creates a general summary report. If there is only one scenario and one replication, the report will be generated automatically. Otherwise, you must select the type of report you want from the dialog below.

general report type selection window

Scenario: Each scenario is listed by name. Select one scenario or All . If you select All, a report will be created for each scenario in separate windows.

Replication: Select an individual replication (listed numerically), Averaged , or All. Specifying All  creates a composite report.

Period: If you use the report function in your model, this field allows you to select any of the reports you created.

Options: Clicking this button displays the General Report Options dialog where you can select which detailed statistics are shown in your report and change the font used.

 Important information to be aware of You can also access the General Report Options from the Options \ Customize Current Window menu in the main Output Module window or by pressing the options button on the button bar when the current window is a general report. You must have run multiple scenarios and replications before the Show options will become available.

6.3.8 – Comparing Scenarios Using Selected Statistics

Set up a customized report to compare statistics across many scenarios. Any standard or custom statistic is added and then made persistent to the output report.

Summary

1. On the ProcessModel Output Detail report, click the View Replication Report button View Replication Report Button (From toolbar: View \ Selected Stats).

2. On the Choose Statistics window, select the appropriate Category and then add from Available Statistics and Available Elements. Click the Right Arrow button to add the cross-product of your selections to the Selected Statistics list. Click OK.

Selected Statistics Window

Important information to be aware of Choose statistics that are or aren’t shown: On the Choose Statistics window click Options to add or remove which statistics are shown.

Multiple Statistics Report

3. If you want to see these stats the next time you run your model then click File \ Save Active Chart View.

Selected Statistics Report

The Selected Stats report allows you to create a scenario and/or replication report with only the specific statistics and elements you want in the report. The Selected Stats report is only available if there are multiple scenarios and replications.

Note that more than one report or graph may be opened simultaneously. Each report and graph is contained in its own resizable window which allows you to create several reports and graphs for comparison. When you choose Selected Stats from the menu or click the corresponding button, the following dialog is displayed.

Selected Statistics Window

Report Type – Replication: The only report type available in ProcessModel, this report creates statistics that are averaged over all replications.

Category: Choose from a list of sections or tables of the general report, e.g., Single Capacity Activities, Resources, Variables, etc.

Available Statistics & Elements: Select the statistics you want then select the element for which you want those statistics calculated. Click the right arrow button to add a cross-product of the selections to the Selected Statistics list. The choices listed depend on the category selected.

Remove All: When you click this button, all Selected Statistics will be removed from the list box.

Options: Clicking this button in the Selected Stats dialog displays the Selected Report Options dialog where you can select which statistics are shown and change the font used in your report.

Important information to be aware of You can also access the Selected Report Options from the Options…Customize Current Window menu in the main Output Module window or by pressing the corresponding button on the toolbar when the selected report window is a Selected Report.

Important information to be aware of Sample size should be at least thirty for the confidence intervals to be statistically significant.

6.3.9 – Sample Reports

For sample report screenshots please refer to the Output Report in Chapter 6.2 above.

6.3.10 – Viewing Graphs

Output detail report of ProcessModel - View Menu

From the View menu you can generate state or utilization summary graphs and pie charts.

Important information to be aware of You may open more than one graph simultaneously. Each graph is contained in its own resizable window which allows you to create several graphs for comparison.

6.3.11 – Utilization Charts & Graphs

State or Utilization Summary When you select State or Utilization Summary, you will be able to select the type of graph you wish to create in the following dialog.

The Output Module allows you to create different types of state and utilization graphs to illustrate the percentage of time that activities and resources were in a particular state: operation, waiting, blocked, down, etc.

Output detail report of ProcessModel - State Utilization Graphs

Graph Type With your mouse, select the type of graph you want from the list.

Options Clicking this button brings up the Graph Options dialog where you can modify and edit graph elements.

Output detail report of ProcessModel - Graph Options

Important information to be aware of You can also access Graph Options from the Options…Customize Current Window menu in the main Output Detailed Report window or by pressing the options button on the button bar when a state or utilization graph is the current window.

6.3.12 – Sample Charts & Graphs

State & Utilization Graphs

Activity Utilization Graph

Activity Utilization graphs show the percentage of time that each activity in the system was utilized. ProcessModel allows you to see this information for all of the activities in the system at once.

The Output Detailed Report organizes information for activities and storages by logical locations. These are defined as the activity or storage name itself and a location for the input queue and output queue of the activity.

This activity state graph displays all multi-capacity activities in the model.

Output detail report of ProcessModel - Activity Utilization Graph

Activity State Graphs

Single and Multiple Capacity Activity State graphs show the percentage of time that each activity in the system was in a particular state, e.g. idle, in operation, waiting for arrivals, or blocked. ProcessModel allows you to see this information for all of the activities in the system at once.

Output detail report of ProcessModel - Multiple Activity Capacity States

 

For further enhancement of a particular activity, simply click the mouse on any one of the bar graphs to create a pie chart for that activity as shown below.

Output detail report of ProcessModel - Research Pie

 

Resource Utilization Graph

Resource Utilization graphs show the percentage of time that each resource in the system was utilized. A resource is utilized when it is transporting or processing an entity. ProcessModel allows you to see this information for all of the resources in the system at once.

Resource State Graph

Similar to activity state graphs are resource state graphs which show the relative amount of time each resource spent in a particular state. The graph below shows the state of a resource.

Output detail report of ProcessModel - Resource States

Once again, a pie chart for any resource is just a mouse click away! Click on the bar of the resource and the Output Module displays a pie chart.

6.3.13 – Time Series Plots & Histograms

The time series option allows you to create plots or histograms from user-defined variables. The plot shows the value of the variable over time. The histogram shows the percentage of time that the variable’s value was within certain ranges. This option is available only when replications are not used during simulation.

Selecting Values to Graph

When you select one of the Time Series menu item choices from the View menu or press the corresponding button in the toolbar, the following dialog appears. Time Series information is available only when one replication has been made.

Output detail report of ProcessModel - Choose Statistics for a Plot or Histogram

 Select values for a Plot or Histogram

1. Select a scenario for your graph. (If no scenarios have been run, you will see only Normal Run in this selection box.)

2. Select one or more values from the simulation. To select multiple values, use the Ctrl or Shift keys in conjunction with the mouse or click and drag the mouse across the values you want.

3. Press the right arrow button to add the selection(s) to the list of Selected Values.

4. Repeat steps 1 through 3 to add more values to be graphed.

Remove values from the Selected Values List

1. Highlight the selected value(s) you wish to remove.

2. Press the left arrow button to remove the selected value(s).

Important information to be aware of Use the Remove All button to remove all selected values from the list.

Plot & Graph Options

Options Press this button in the Choose Statistics for Plot dialog (shown on the previous page) to display the following dialog.

Output detail report of ProcessModel - Graph Options

The Graph Options dialog shown above allows you to customize some of the features of the plot or histogram.

Important information to be aware of You can also access this option dialog from the Options…Customize Current Window menu in the main Output Program window or by pressing the options button on the button bar when a time series graph is the current window.

Labels Selecting one of the labels allows you to customize certain attributes for that label such as font, color, and the text associated with the label. Not all attributes apply to all labels. This allows you to customize the look of your graph.

Axis Attributes When one of these is selected (X-Axis or Y-Axis), the other options in the box apply to that axis.

• Grid Lines Show grid lines for this axis.

• Exact Values Show the values of the data points for this axis.

• Sig Digits Number of significant digits to show on this axis.

• Time Scale If this axis pertains to time, show it using these units.

• Range Zoom range for this axis of the graph. Changing this affects the scrolling range for each click on the scroll bar for this axis.

Plot (or Histogram) Options When this button is pressed, one of the following dialogs is displayed depending on the Graph Type you selected.

Plot Options

Output detail report of ProcessModel - Plot Options

Name Use this list box to select which value’s options you will modify. If you select All, the options for all the values will be changed simultaneously.

Alias The text entered here will appear on the graph instead of the actual value’s name. This option is useful in improving the appearance of your graph.

Color Change the plotting color for the value selected. (Not available if All is selected in the Name box.)

Style Check the box next to the style of graph or chart you want.

Plot Type Select the plot type you want to use. Some types may not be available for certain types of data. The types are as follows:

• Normal Plots the value for every change over time.

• Periodic Average Plots the average value by period over time (e.g., the average contents of an activity by hours).

Period Enter the period over which the periodic plots will be averaged or summed.

Histogram Options

Output detail report of ProcessModel - Plot Options

Name Use this list box to select which value’s options you will modify. If you select All, the options for all the values will be changed simultaneously.

Alias The text entered here will appear on the graph instead of the value’s actual name. This option is useful for improving the appearance of your graph.

Style Check the box next to the style of graph or chart you want.

Range The range for your histogram. If the data range is larger than indicated here, end bars will be added to make the graph correctly show the real range.

Bar Width The width of the histogram bar cells.

Bars Shows the number of bars that will be used in the histogram based on the range and bar width.

6.3.14 – Sample Plots & Histograms

Time Series Histogram

The following histogram for a variable shows the percentage of the simulation time that the variable’s value fell within one of many ranges.

Output detail report of ProcessModel - Time Series Histogrm

This histogram provides an excellent view of the variable’s behavior in the model.

Time Series Plots

The following Time Series plot for a variable shows the value history of the variable over the hours simulated.

Output detail report of ProcessModel - Time Series Graph

Rather that looking at a simple average for the entire simulation, this plot provides an excellent view of what is happening to the value of the variable over time in the model.

6.3.15 – Exporting Reports

Exporting General Reports

1. With General Report open, click File \ Save As choose the type of export you want to create under Save as Type (text .txt or Excel .xls) and click Save.

Important information to be aware of A report can also be printed to PDF using the Microsoft Print to PDF tool available in all the latest versions on Windows. To print to PDF simply click File \ Print and select Microsoft Print to PDF as the name of the printer, click OK to open a dialog to save the report as PDF.

export output detailed report results

Export Variable Information

1. Click Generate Time Series Plot button (or Generate Time Series Histogram or View \ Time Series \ Plot or Histogram).

2. Add the variables required to Selected Values and click Export Data.

3. Choose the type of export you want to create under Save as Type (.csv or Excel .xls) and click Save.

Important information to be aware of Exporting variable data in .XLS format has a limit of 16,384 rows. Exporting variable data as a .CSV has a limit of 1,000,000 rows. Only one variable can be exported at a time in .CSV.

saving variable export data window

Important information to be aware of Exported data has two parameters, the value of the variable and the simulation time at which that variable changed.

Output detail report of ProcessModel - Export to Excel

Exporting Chart Data

1. Click Generate Time Series Plot button (or Generate Time Series Histogram or View \ Time Series \ Plot or Histogram).

2. Add the variables required to Selected Values and click OK.

3. Click File \ Export to save chart information in .csv.

6.4 – Analyzing Output Data

The primary reason for using ProcessModel is to make better decisions that will result in achieving the goals of the company, organization, or group. The reports and graphs created using the Output Module can provide you with the information you need to make these decisions.

You will be able to identify problems and opportunities that may not have been readily apparent at the outset. The data may also confirm and validate what your common sense already told you. You can find potential processing bottlenecks, under-utilized resources, or unused capacity.

You can analyze the throughput of your system, evaluate inventory level effects on system performance, or you can completely change the process and see the cost and time savings. You could determine whether improved throughput justifies the costs of adding a new activity or resource to the system.

6.4.1 – Prepare the Model for Making Decisions

Validate and Verify the Model

Substantial decisions are often implemented because of the model created. It is crucial that the model be properly Validated and Verified. The amount of time spent in this area is dependent on the system and the goal of the model.

Let’s start by dispelling the myth that you can create a perfect model that will represent your system in complete accuracy. A computerized model will never be totally accurate. “All models are wrong. Some are useful 1 ” supports the concept that building a process model is a series of trade-offs. The degree of how “useful” a model must be balanced with the fact that greater accuracy increases cost and time to create the model. The following diagram illustrate the cost /accuracy relationship in building the model.

Validate and Verify the Model

Validation is usually defined to mean “substantiation that a computerized model within its domain of applicability possesses a satisfactory range of accuracy consistent with the intended application of the model.Information Icon

Verification is often defined as “ensuring that the computer program of the computerized model and its implementation are correct.Information Icon

Techniques for Validating a Model

Animation: Watch the animation for operational correctness as the model moves through time. For example, the timing build up of customer queues may be observed and compared to the actual system.

Event Validity: The “events” of occurrences of the simulation model are compared to those of the real system to determine if they are similar. An example of events would be the number of entries into an activity or total exits from the system.

Extreme Condition Tests: The model should work of any level (or even unlikely) of extreme conditions. For example, if raw material run out then total output should reflect the stock out condition.

Face Validity: Ask knowledgeable people in the real system to review the portion of the model that they are familiar with. Are the general relationships correct? Are the queue buildups occurring to the level and timing of the real system?

Fixed Values: Replace distributions and variable inputs with constants, then determine if the model results correlate with easily calculated values.

Historical Data Validation: Compare the simulation output with know historical data. Does the model output compare with real data. Use Stat::Fit to view the cycle time, total completions, or custom metric data from the model and again for the real system.

Operational Graphs: Plot key information to Time Series Plots. Do the plots accurately reflect the time dependent fluctuations of the real system.

Traces: Use Display, and Debug statements to follow individual entities through the model. Verify the that the flow is the same in the model as the real system. The previous tests are a summary from an article written by Sargent. Information Icon

Techniques for Verifying a Model

Model Review: Use a structured walk through procedure with another individual to force a methodical look at usage of the modeling objects. Has each feature been used in an allowable way. Are the metrics collected in the model appropriately.

Laws of Conservation: Check the quantities at stages of the model to determine if entities are prematurely exiting, or if batching or creating are producing unintended results.

Simple Test Cases: Complex logic of the model should be tested independently to assure proper function. Creation of a small test case will help to eliminate errors caused by the confusion created of a large model.

Input Data Checking: Have input data been interpreted correctly? Have distributions been properly fit?

Integrate Production Metrics Into the Model

In addition to built-in metrics, custom metrics can be defined for any specific area you desire to track. For example completions per hour, dollar production per day, defects per million, etc. can tracked and reported. See section 10.9.1 through 10.9.5 for examples of how to integrate custom metrics.

Determine if a Warm Up Period is Needed

You need to determine if you are studying the transient periods of the model or the long-term steady-state. The transient period is when there is no consistency in the statistical variation of the performance variable of the system. Some systems will always be in a state of transition and that may be what you want to study. Other systems run at a steady-state, and don’t experience transitional periods from day to day.

When we model steady-state system we have to load the simulation with entities so that it will approximate the steady-state. We call this starting period a Warm-up time. You will need to determine the time length of the warm-up time and toss out that data. Fortunately ProcessModel has an easy way to cut off the data that you don’t need and report only the good data.

Determining the length of the warm-up period is determined by what you are interested in studying and accomplished largely by inspection. For example if you are studying work-in-process you could plot the WIP to a variable and view the graph to determine the approximate time the system transitioned to steady-state.

Steady state

In the above example the warm-up period would be set to 8 hours. Data collected prior to 8 hours will be discarded.

How To – Set up a warm-up period

1. From the Simulation menu, select Options.

2. Enter the length of the warm-up period in the  Warmup Length field.

Output detail report of ProcessModel - Warmup Time

Determine the Number of Replications

Simulation modeling is a sampling technique. What this means is, when you run a simulation for a week, you are taking a sample reading of what a week’s result could look like. Another week may be very similar or very different. The point is, that you don’t know if your single sample will be fairly accurate or an outlier in a wildly varying system. Simulation can help you to determine how much variance can be expected and what the range of numbers can be expected for the output you choose to sample.

The sampling method requires a recognition that the answers you derive from a simulation will likely have a range rather than a point estimate. If you were speaking of production rates per hour, you may provide an answer like “Ninety-five percent of the time we will be able to produce between 50 to 62 items per hour.”

In order to obtain these samples from your model you will need to run multiple replications. Multiple replications allows your model to run repeatedly with different starting values for the random numbers which will provide variation in the output reports. Multiple replication reports will help you to determine the expected range for the performance variable being studied.

There is seldom agreement by different authors on how many replications to run because that number is dependent on many variables (type of system being modeled, statistical variation of the system, accuracy needed, etc.). A good rule of thumb is to use a minimum of 30 replications. As the need for accuracy increases you can statistically determine the number of replications needed for your specific circumstances by using SimRunner (see “Analyze Model”).

How To – Set up Multiple Replications

1. From the Simulation menu, select Options.

2. Enter the number of replications for your model.

6.4.2 – Making Decisions With Output Reports

Making decisions with the output reports provided by ProcessModel is quick and simple. Two reports are almost always used while others are used in varying degrees. First, the Total Cost in the Output Summary report is valuable in identifying dollar improvements for system changes. Second, Cycle Time report from the Output Summary identifies the improvement in total time in the system. Other specific metrics can be created to track items important to your company. Those reports will often be reported as variable statistics and can also be found in the Variable Statistics report of the Output Summary. These reports are your measurements and all other reports will help you to uncover how to affect the measurements. These other reports will be found primarily in the Output Detail reports. The following is a list of how these reports may be used to make decisions to affect the measurements.

Perform Bottleneck Analysis

By focusing effort on the system delays you can quickly narrow the scope of the process improvement efforts, saving time and money. Sort the all of the activities, storage and queues by Average Minutes Per Entry. Use a Pareto analysis to show the high impact areas for change.

Performing Bottleneck Analysis

1. Run the model to completion.

2. View the output report.

3. Make certain the General Output report is selected. Save the output to an Excel format by selecting File then Save As . Choose Save As Type to be MS Excel file and press the Save button.

Output detail report of ProcessModel - Saving Output Report

4. Open Excel and locate the file that was just saved.

5. The tabs at the bottom of the Excel file represent the sections of the output report.

Output detail report of ProcessModel - Export to Excel

6. Once exported, you can use any of Excel’s tools to do a variety of reports to further analyse your simulation data using charts, graphs, etc.

Important information to be aware of You could do such things as combine the times for the activities with it’s corresponding input or output queue to perform a bottleneck analysis. This analysis makes it possible easily see where delays are occurring in the system and what activities should be ignored.

Review Resource Usage

Examine the Resource State graphs for areas of resource over and under utilization. Opportunities for cross training and resource elimination can quickly be identified. Use this graph for quick generalizations and to identify if bottlenecks are occurring because resources are over utilized. Be careful that resources state generalizations don’t cover the possibility that resources may be over utilized part of the time and under utilized at other times.

Highly utilized resources may prove to be one of the major causes of high cycle times. A general rule for resources is that a utilization higher than 70 percent is not sustainable for long periods of time. This general rule is dependent on the type of work, stress level and length and duration of work spikes. Often times, the utilization will need to be lower. Watching the measurements while adjusting the number of resources and work schedules creates view of the business that has likely never been available.

Time Series Plots and Histograms

Time Series Plots allow a graph to be created that shows the timing of the changes of an important measurement. The time relationship of the changes in a measurement makes it possible to determine when, for example, the cycle time increases during the day and if a proposed change will effect it.

Histograms allow you to see the frequency of changes to the measurements.

Important information to be aware of Any measurement that can be reported to a variable can be plotted.

Many other reports are available in ProcessModel. In each case you will find that these reports help to determine how to affect the measurements.

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