Allocating work resources in Project is a nightmare

Nov 17, 2022 | Project Hints and Tips

If you are using Microsoft Project and are allocating work resources in your plan (these are normally people) you may have felt that Project has a mind of it’s own!!  Particularly what happens to the duration of the tasks when more than 1 resource is addedIt is important to understand how it behaves so that you can allocate your resources with confidence. 

All mention of resources throughout the rest of this blog are related to work resources only and assume that the resources are added at 100% for their maximum units unless otherwise statedIt is also assumed that the calendar is configured so that a day of work is 8 hours. 

Allocating a single resource to a task

When a single Work resource is added to a task the duration of the task remains unchanged. 

e.g. If the task is 2 days long and a resource is added to the task the duration of the task will remain at 2 days and a total of 16hrs work will be completed. 

Allocating Multiple resources to the task at the same time 

1. Select the Assign Resources icon from the Resource tab 

Assign resources icon

2. Select both resources and click on assign 

Assign resources dialog

When multiple resources are added together then the duration of the task remains unchanged but the work increases. 

e.g. If 2 resources are added to a 2 days task each of them will be working for 2 days at 8 hours per day.  So, each will be working 16hrs giving a total hours worked of 32hrs 

NOTE: This also behaves in the same way if a resource is added at 200% before it is assigned. 

Allocating Multiple resources one after the other 

This is where the allocation is a little more tricky! 

  1. Select the Assign Resources icon from the Resource tab 
  2. Select the first resource and click on assign, then select the second resource and click on assign 

When this is done it initially behaves in the same way as allocating resources together.  However, a smart tag will appear giving choices. 

Smart tag 1
  • Reduce the duration but keep the same amount of work 

e.g. If a resource is added to a 2 days task, then a second resource is added each resource will now be working 1 day at 8 hrs per day giving a total hours worked of 16hrs.  This is an example of effort driven scheduling where if we throw more resources (effort) at the task then the time taken to complete the task reduces. 

  • Increase the amount of work but keep the same duration (this is the default) 

e.g. If a resource is added to a 2 days task, then a second resource is added each of them will be working for 2 days at 8 hours per day.  So, each will be working 16hrs giving a total hours worked of 32hrs. 

  • Reduce the hours resources work per day (units), but keep the same duration and work 

e.g. If a resource is added to a 2 days task, then a second resource is added each of them will be working for 2 days at 50% capacity (reduced units) equating to 4 hours per day.  The total hours worked will be 16hrs.  This would give the resources the capacity to work on another project at the same time, also at 50% capacity with no overallocation of resources. 

NOTE: The behaviour is slightly different if a resource is assigned at 100%, then this is changed to 200%.    When this is done there are only 2 choices and the default is different. 

Smart tag 2
  • Change the duration but keep the amount of work the same (this is the default) 

e.g. For a 2 days task the duration would reduce to 1 day with 200% allocation and the number of hours worked would be 16hrs in total 

  • Change the amount of work but keep the duration the same 

e.g. For a 2 day task the duration would remain at 2 days with 200% allocation on each of these 2 days and the number of hours worked would be 32hrs in total. 

Further Reading

If you’ve enjoyed reading how to allocate work resources in Microsoft Project, there’s some other blogs below that you might find useful:

Want to learn more about Microsoft Project? Then email lara@laramellortraining.co.uk to discuss how I can help or have a look at the Microsoft Project Courses I run.