# Schedule Formula - Duration, Units And Work In Microsoft Project 2013

I hope you are following my articles and blogs on Project Server technology.

Read my previous articles for better understanding,

In this blog, I will explain to you how to calculate the duration, work & units formula in Microsoft Project 2013.

Afterwards, we create a task but before assigning a resource to it, the task has the duration but no work is linked with it.

Since the work represents the amount of an effort; a resource will be spent to complete a task.

For example:

If you have one person, who is working full time, the amount of time measure as work is the same as the amount of time measured as duration. In general, the amount of work will match the duration unless you assign more than one resource to a task or the one resource which you assigned is not working full time.

Microsoft Project calculates the work, using scheduling formula given below.

Duration * Assignment units = work

Let me give you another example in detail. The duration of task3 is one week or 5 working days. For the new project, five days are equal to 40 hours. When we assigned a resource (name as Prem) to task3, the project applied 100% of prem working time to this task.

Hence, the scheduling formula for task3 looks, as shown below.

40 hrs(task duration) * 100% assignment units = 40 hrs of work

If you think in a holistic way, we can also assume as prem is assigned to task3 at 100% units, where the tasks should require 40 hrs of work.