IBM Certification Test 992.3 - Simulation
Understand how resources and roles are allocated during simulation
Role and resource behavior in simulations
Roles and resources have specific ways of behaving during a simulation run that are important to understand.
Costs for resources and roles
If you define costs for both resources and roles, the resource cost takes priority. Role cost is used only if no other cost is associated with the resource.
When you simulate a process containing an activity that has a requirement for a role, the resource cost of the activity is based on the cost of the qualified resource that is allocated to the activity. For example, if the Customer Service role has a cost of $25 an hour but the individual resource that is assigned to the activity, John Doe, has a cost of $22 an hour, the resource cost will be based on $22 an hour. If no cost is defined for the allocated resource, the role cost is used to determine the activity resource cost.
Resource and role allocations
Note: The following information refers to resources, but applies equally to roles.
There are no rules to govern the resource allocation for simulations. When you run the simulation, the process can use any of the resources that you have made available in the resource pool for the process. If more resources are available than are required to complete a particular activity, the simulation randomly chooses adequate resources to meet the requirement. This can produce variations in the cost of completing the activity, if the available resources have different costs.
When a resource is allocated to an activity during a simulation, if the process instance is ended before the period of allocation is complete, the resource is deallocated from the activity and can be allocated elsewhere. In the simulation results, however, resource allocations are recorded for the complete period of the resource requirement and incur their full costs.
A resource allocation may be split into multiple intervals, if the allocated resource is not continuously available for the entire duration of the resource requirement.
If you set the process to Use resources' time required as a task processing time, the processing time of each activity is equal to the duration of the longest resource requirement. Otherwise the processing time may be longer or shorter.
If a resource assigned to the activity is not continuously available for the duration of the activity, it is possible that the resource will remain allocated to the activity even after the activity completes. For example, if an activity takes 2 hours to complete, but the required resource is only available in 1 hour increments with half hour breaks, and the activity starts at 2:00 p.m., the activity might record a completion time of 4:00 p.m. while the resource records a completion time of 4:30 p.m. To avoid this behavior, you can set the Wait for resources' end time to compete a task option. With this option set, both the task and resource will record a completion time of 4:30 p.m.
- A task starts execution (begins “processing time”) once it acquires all of its required resources
- Allocation is complicated by the resource allocation schedule
- A resource remains allocated to a task instance for its duration
- May be specified differently via the “time required”attribute on the resource
- Resource allocation can generate the resources based on a role
- Available from the Resource Pool tab for a process
Related links
- Business Process Management: Modeling through Monitoring Using WebSphere V6.0.2 Products
- WebSphere business process management zone (IBM Developerworks)
- WebSphere Business Modeler certification exam 992 prep, Part 3: Simulate business processes
- WebSphere Business Modeler certification exam 992 prep, Part 3: Simulate business processes (pdf)
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