From the course: Project Management Foundations: Schedules

Keep an assignment variable fixed - Microsoft Project Tutorial

From the course: Project Management Foundations: Schedules

Keep an assignment variable fixed

“

- [Instructor] Many scheduling tools let you choose whether to keep duration, work or resource units fixed when you modify resource assignments. If you estimate work for your project activities, it makes sense to keep work fixed. With this approach, you add resources and their availability to the project. When you enter the work and assign resources to each activity, your scheduling tool calculates duration. If you change the resource units on an assignment later, such as adding another resource, the tool recalculates duration, while keeping the work the same. If you change the duration, the tool recalculates the resource units you need to finish the work in that timeframe. Another option is to keep duration fixed. This is a good choice. If you don't assign resources to activities, or you must complete activities in the duration that's been given. Fixed duration has an added advantage. You can specify duration to the accuracy you prefer such as whole or half days. As you change assignments, your scheduling tool won't change the duration to a fractional duration like 1.667 days. With fixed duration, you specify work and the tool calculates the resource units needed to complete the task. The third option, of course, is to fix the resource units. In most organizations. This option is rarely used because work or duration take precedence. However, I use it a lot. I use a scheduling tool to manage my work. There's only one of me, so my availability is fixed unless I decide not to eat and sleep. Because I keep resource units fixed, the scheduling tool calculates duration based on the work I estimated. If the work changes, the tool adjusts the duration. Suppose I have a hard deadline that I have to meet. Then I simply override the resource units to keep the duration the same. Bottom line, keep units fixed only if you can't increase resource availability. Your scheduling tool might have a feature to designate activities as fixed duration or variable duration, also known as effort driven scheduling. Effort driven scheduling means that the total activity work remains the same regardless how you modify resource assignments. Basically it's the same as fixed work. For example, if an activity is set to fix duration and effort driven scheduling, and you add another resource, the tool recalculates resource units, because both duration and work are fixed. Meetings are not controlled by effort driven scheduling because the total work doesn't stay the same as you add or remove attendees. If you add attendees that total work increases. If you cut people from the roster, total work decreases. Choose the variable you keep fixed based on how you schedule your projects.

Contents