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%Complete calculation
Question

I'm currently using %complete (not %work complete) to track project progress. I know that % complete formula = (Actual duration/duration)*100. But when I plug in this formula, %complete that I got still doesn't make sence. For example, Task A duration is 5 days, 80 hours. My calculation setup is 8 hrs/day but my business working hours is MonThurs 8.75 hrs and Friday 5 hrs (I don't know if this is related to the formula). When I mark 25% complete, 20 hours is stored as actual. If I do per the formula my %complete should be actual 20 hrs=2.5 days, then (2.5/5)*100 = 50%......What's wrong in my calculation?
Answers

Mimi,
Okay, I assume you understand why you get the results you do after your first entry on 10/24. The unnamed resource worked one full work day (8.75 hours) which when divided by the standard 8hr/day yields an actual duration of 1.09. No surprise there, the plan is "on track" so the duration is still the original 5 days.
However on the second day the resource worked more than one full work day (i.e. an extra 1.25 hours). Okay, new ball game because you are now ahead of plan by 1.25 hours. Based on this current status it will now take 1.25 hours less in total duration to finish the task, but the total work content is still 40 hours. Therefore, Project has adjusted Friday's work content to be 3.75 hours, which means the task will finish in only 4.84 days duration.
Since duration is defined as the time interval (normally in working time) between the task start and finish you can use a couple custom fields to calculate both Actual Duration and Duration. Try it. Insert a couple of extra duration fields (e.g. Duration1 and Duration2) into the view and customize them with the following equations (Note: I have defined your custom work week calendar as "mimi"):
For the Actual Duration calculation,
Duration1 = ProjDateDiff([Start],[Stop],"mimi")
For the Duration calculation
Duration2 = ProjDateDiff([Start],[Finish],"mimi")
To help visualize these equations it might help to add the time to the Start, Finish and Stop fields (File/Options/General group  pick a date format that includes the time).
Does this help?
John
 Proposed as answer by Julie SheetsModerator Monday, October 24, 2011 8:08 PM
 Marked as answer by Mimi Laongpanich Thursday, October 27, 2011 7:57 PM
All replies

Mimi,
I'm a little confused. If you mark the task as 25% using the %Complete field then why would you expect it to be 50%? I think you are mixing up duration and work. You say the task is 5 days, 80 hours, so you most likely have a fixed duration type task of 5 days duration with 80 hours of work content. Now when that task is marked as 25% complete, the Actual Duration field is 5 days x 25% = 1.25 days. The Actual Work field however is 80 hours x 25% = 20 hours.
By the way, you can customize your project and/or resource calendars to have any number of work hours per day but when Project calculates duration it goes strictly by what is set under Tools/Options/Calendar tab for "hours per day".
John

Mimi,
What is happening is a common error/issue. Before you enter any duration information you should go to the Calendar options and set the hours per day to 8.75. In its default state, 8 hours per day, you have told the program that only 8 hours of duration will be done on each task per day, when you are actually doing 8.75 hours per day of duration.
When you set the project calendar, set your Friday work hours (e.g. 8:00 AM to 2:00 PM with a one hour lunch). This will make things slightly difficult if you have small durations (1  5 days) but it will all come out in the wash.
Hope this helps.
Gregg D. Richie, PMP, MCTS; Author, Microsoft Project 2010, Microsoft Official Academic Course Series 
Even though I work 8.75 Hrs MTH/ 5 hrs Fri, total hours/week is still 40 hrs. If I set 8.75/day in Calendar options and enter 5 days in schedule, total work hours will be 8.75x5 = 43.75 instead of 40 hrs. In the sence it's wrong, because when we schedule 5 days of work, it should equal 40 hrs.
Is there a field that stores actual duration? Can I enter work hours in Task usage and come up with %Complete and how it's calculated to %Complete?

Mimi,
Rather than take some time to reiterate, has this post effectively been superseded by your later post? That is, does it answer your question? If not, please let us know which questions you still have. If your other post answers your questions please mark this one as answered so it can be closed out.
Thanks.
John

I now understand about %complete. MSP seems to calculate correctly when I only mark progress through %complete. However, when I update Actual work through timephased, I can't figure out the formula used for Duration. I setup 8 hrs/day in calculate option. However, MTH is 8.75 hrs, F is 5 hrs. On 10/24, I record actual hours 8.75, Actual duration becomes 1.09 day and total duration is still 5 days. On 10/25 I record 10 hrs, then total duration changed to 4.84 days. What is a formula behind the scene?

Mimi,
Okay, I assume you understand why you get the results you do after your first entry on 10/24. The unnamed resource worked one full work day (8.75 hours) which when divided by the standard 8hr/day yields an actual duration of 1.09. No surprise there, the plan is "on track" so the duration is still the original 5 days.
However on the second day the resource worked more than one full work day (i.e. an extra 1.25 hours). Okay, new ball game because you are now ahead of plan by 1.25 hours. Based on this current status it will now take 1.25 hours less in total duration to finish the task, but the total work content is still 40 hours. Therefore, Project has adjusted Friday's work content to be 3.75 hours, which means the task will finish in only 4.84 days duration.
Since duration is defined as the time interval (normally in working time) between the task start and finish you can use a couple custom fields to calculate both Actual Duration and Duration. Try it. Insert a couple of extra duration fields (e.g. Duration1 and Duration2) into the view and customize them with the following equations (Note: I have defined your custom work week calendar as "mimi"):
For the Actual Duration calculation,
Duration1 = ProjDateDiff([Start],[Stop],"mimi")
For the Duration calculation
Duration2 = ProjDateDiff([Start],[Finish],"mimi")
To help visualize these equations it might help to add the time to the Start, Finish and Stop fields (File/Options/General group  pick a date format that includes the time).
Does this help?
John
 Proposed as answer by Julie SheetsModerator Monday, October 24, 2011 8:08 PM
 Marked as answer by Mimi Laongpanich Thursday, October 27, 2011 7:57 PM

