Task type and Effort driven in Microsoft Project

I usually do not do Microsoft Project any more, but since there is a Project integration in TFS, I sometimes get some questions. And since people use MS Project, they fall into the task type hell.

When you work in the task views like Gantt Chart you work with the task table in the project database. In this database you have three, connected, fields, namely Work, Duration and Unit. Connected by a formula. Namely:
Work=Duration *Unit
Work is most of the cases have the metric Hours, Duration have the metric Days and Unit % (even if these are settings found in the wonderful Settings dialog box under the Tools menu). So one example can be:
80[h]=10[d]*1
Which means that if one person works full time during ten days this results in 80 hours work. So the definitions of the fields are:

• Work = man hours to be spent
• Duration = number of working days between the start of the work and the finishing of the work
• Unit= Percentage of time spent on the task

If you question my using the 8 hours a day, this is the default setting in Project. And yes, you can change this too.

If you want to try all of this stuff, you need to show all the fields in the view: the easiest way is right clicking a column name and inserting a new column. Select Unit and Work (you need to do this one column at the time) and since Duration is visible by default, you now get the complete picture.

So, now you can start playing around with the figures. (One tip though, never add Work before you set a resource on a task, then you're in for a real challenge. And also, never set a resource on a task with sub tasks. But now, back on track).

When you start changing the values in one of the columns, you can see that the other values change. But how do you know which one? Well, on the task table there is also a field called Task type and this value specifies which column should not change when you change the other values. This means that if you set this column to Work, the Work column will not change if you change Unit or Duration. Get the picture? If not, e-mail me.

What you also can remember is that there is another column: Effort driven: if you set this column to Yes, adding new resources will divide the current work on the task between all the new and current resources. But is that not always true, you think? Well, imagining creating a task for a meeting. If this task has Effort driven set to yes, adding new participants decreases the length of the meeting...

So, what should you choose? Well, you choose depending on task:

• Work
  When you know how much work will be spent. Often used for development tasks when you have an estimation in hours (this will take me 40 hours to program)
• Duration
  When you know how much calendar time a task will take. All meetings for example. And tasks where the estimations are in the terms "it will take us three weeks to be ready". Should always be set without Effort Driven
  
• Unit
  When the focus factor of the participants cannot change. When you have a resource on 40% and this will under no circumstances change.

When creating a project file, be sure to have these columns visible so you know what you're doing. And if you know that you will only use one setting, please free to visit Tools-->Options to set which setting all new tasks will have.