Tuesday, January 27, 2009

Analyze process duration

How to Analyze process duration

Perform a process duration analysis to examine the average durations of all process cases in a simulation.
You need to run a simulation based on a process that you have modeled before you can do a process duration analysis.

This analysis provides information on the average durations for the cases in a simulation. It is a subset of the information available in the Process Cases Summary analysis, but can be used to create a cleaner presentation of the data.

In this analysis, elapsed duration is the duration that a process case takes if started at a specific time and date. Elapsed duration includes transfer times between activities and the elapsed durations of all activities on the critical path. The critical path is defined as the processing path that has the longest duration of all parallel paths in the process case. Calculations are performed per case by getting the simple average of the process instances' duration records for each case.

Use this analysis when you want to examine process level processing durations and throughputs for each of the process cases that the simulation generates. This analysis, like other process case analyses, may reveal unexpected results within specific process cases. For example, you may determine that the average throughput in a particular process case is unacceptably low. As a result of reviewing the information that this analysis presents, you may decide that you need to modify a process model or reset resource levels, or you may determine that you want to investigate further with another type of process case analysis such as process resource analysis. Alternatively, you can examine the duration results for specific process instances within a process case by running the process instance summary analysis and then the process instance time analysis.

To analyze process durations, complete the following steps:

 

  1. In the Project Tree view, right-click the simulation result that you want to analyze, and then select Dynamic Analysis > Process Cases Analysis > Process Duration. A window appears.
  2. Select the type of process instances you want to include in the analysis:
    • Succeeded process instances only
    • Failed process instances only
    • All process instances
  3. Click Finish. The window closes.

 

Now, you can view the results of the analysis in the Analysis view. You can also print a report of the results.

Specifying duration

You can specify the processing time for an element such as a task or process. This is the time while the element is actively executing, rather than the elapsed time, which may include delays while waiting for a resource. For a task, you can also specify the maximum amount of time that the task should wait for a resource before failing.

If you specify values, you can run simulations based on them. You can also choose to override the values by selecting the element in the simulation profile and changing its values in the Attributes view. If you do not specify values, the default values specified in Window > Preferences > Business Modeling > Simulation > Tasks are applied when you create a simulation snapshot.

By default, durations are unspecified. You can remove a specification by selecting None from the drop-down list.

Setting processing duration to equal resource duration

You can specify that processing durations for activities in a process should always be equal to the resource requirement that has the longest duration for the activity.

To set processing duration to equal resource duration, you must be working in an existing simulation profile that you have created.

Sometimes the time that you model for an activity to be completed and the time that a resource must be allocated to work on the activity do not match. For example, an activity might be modeled with a random duration between 4 and 6 hours, but the resource assigned to the task might be on a contract with terms that state that it is only available for 6 hour assignments. Therefore, even if the task takes 4 hours, the resource is still considered allocated and unavailable to other tasks for a full 6 hours. In this case, it makes sense that you want to record different processing times for the task and for the resource assigned to it.

Sometimes, the time that you model for an activity to be completed is completely defined by the amount of time that your resource must spend working on it. You might have different possible resources you can assign to the activity, with different amounts of time they require to carry out the activity. In this case, you can use the Use resources' time required as a task processing time setting to force the activity's time requirement to be equal to the resource allocation time requirement.
 
 

 




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