Hi,

I noticed that lot of MS Project users have a problem with Duration and work which was already completed. Let me give you an example in MS PROJECT 2016.

Let’s say that we have a one Task Project, with 4 Days Duration, and John is supposed to work on that Task:

As you can see John is going to spend 32 hours of work (4 days * 8 hours per day = 32 hours).

Now let’s say that Task is 50% completed:

and we get:

Now let’s say that we made a mistake. Task was originally meant to have Duration 3 days, and Task is 50% completed.

I will change Duration from 4 to 3 days and I will get:

As you can see, when I changed Duration form 4 to 3 days, work has changed from 32 hours to 24 hours (3 days * 8 hours per day = 24 hours). Actual Duration and Actual work remained intact, and % complete is now 67%. Why? Because 2 days (Actual) / 3 days (Total9 = 0,67, e.g. 67%.

Remember this: Actual means – already done! if you don’t change it it will remain as it is no matter if you change Duration or Work.

So, back to the Case. If we want to have a Task which has 3 days Duration and is completed 50%, we should follow next steps:

1. This is the moment when we noticed that we have mad a mistake. So Duration is 4 days and % Complete is 50%:

2. First we will put 0% Completed:

and we will get:

3. Now we will change Duration from 4 to 3 days:

4. Finally we are going to make it 50% completed (as we did before, when Duration was 4 days), and we will get:

Now we have what we wanted at the first place. Of, course, same steps should be taken if we want to increase Duration!

Regards!