Microsoft KB Archive/111280

Project: Actual Work in Task Table May Change Unexpectedly

PSS ID Number: Q111280 Article last modified on 10-14-1994

3.00 3.00a

WINDOWS

= SYMPTOMS =

When you enter actual work in a task table, Microsoft Project may change the entered value.

= CAUSE =

This behavior occurs as a result of the way Microsoft Project calculates actual work on a task table when resources are assigned.

Microsoft Project calculates actual work with the following formula:

Actual Work = (Task Work/Sum(All Resource Units))xResource Units

= MORE INFORMATION =

Steps to Reproduce Behavior

 * 1) Use a dual-pane view with a task sheet on top, and a task form on the bottom.
 * 2) With the task sheet active, choose Work from the Table menu.
 * 3) Enter a task with a duration of 8h, and assign 1 unit of a resource to the task.
 * 4) Change the resource units to .86.

The Duration should now be 1.16d, and work should be 8h.

 On the task sheet, enter 8h in the Actual Work field.

The actual work will be recalculated to 7.98h.

Explanation
Microsoft Project calculates actual work with the following formula:

Actual Work = (Task Work/Sum(All Resource Units))xResource Units (in this case Actual Work=(8h/.86)x.86)

Because Microsoft Project stores 8h as 480 minutes, 480/.86 = 558.1395. Microsoft Project rounds the 558.1395 to 558 x .86=479.88, which is then rounded to 479. Microsoft Project then converts this value back to hours as 479/60 = 7.9833, which is rounded to 7.98.

KBCategory: kbusage KBSubcategory:

= Additional reference words: 3.00 3.00a =

Copyright Microsoft Corporation 1994.