OWB Autoschedule does not schedule correctly when Max % Load is set to 100% and Resource Constraints is Checked

Document ID : KB000029379
Last Modified Date : 14/02/2018
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Issue:

Open Workbench (OWB) Autoschedule does not schedule Fixed Duration tasks correctly when Max % Load is set to 100%, Loading Pattern is set to Uniform, and Resource Constraints is checked. It pushes task dates and ETC out and changes task duration.

Notes:

  1. This issue does not occur if Resource Constraints is unchecked when Autoscheduling.
  2. There are no project or task dependencies or constraints. 
  3. There are no actuals on the tasks.
  4. All Tasks are set to Fixed Duration.
  5. This issue doesn't occur when Loading Pattern is set to Fixed, only if Loading Pattern is set to Uniform. 

Steps to Reproduce:

  1. Create a project in CA PPM 
  2. Add one resource to the project who has 8 hours of availability and is allocated 100% to the project 
  3. Create 3 Fixed Duration tasks with the same Float, Priority, Start/Finish dates and ETCs 
  4. Assign the same resource to all 3 tasks with the same Start/Finish dates. Loading Pattern should be Uniform and no actuals added 
  5. Open the project in Open Workbench 
  6. Click on the Project tab, then click the Autoschedule button 
  7. Update the Start date to be the Start Date of the project 
  8. Ensure Resource Constraints is checked and click OK 
Expected Results:  ETCs spread out evenly and Task Start / Finish Dates and duration units remain the same. 
 
capture2.jpg

Actual Results: For some of the tasks, ETCs and Task Start / Finish dates get pushed out and the durations of the tasks are shortened. 

Capture.JPG

 

 

Resolution:

Autoschedule is working as designed and documented. The Uniform loading pattern is special when it comes to how it works with Max % Load. If the % of availability is less than the Max % Load then those days are not scheduled when the loading pattern is Uniform. Either the Max % Load or the loading pattern can be changed to to bring in the task. This behavior is documented. Here's a snippet from the documentation:

Uniform Loading Pattern

 

This pattern assigns resource time evenly across a task only on those days when the resource is available to meet the task requirements. For example, if a resource is scheduled to work four hours per day on a task, the resource will not be scheduled to work on that task on days when the resource is only available to work on the task for three hours. The maximum percentage and resource availability is taken into account when assigning resources to tasks using this loading pattern.