Project Scheduling Constraints

In Microsoft Project constraints can be used to create a link between a task and a particular date. By default all tasks are created with the Constraint type ‘As Soon As Possible’ set. This allows Microsoft Project to schedule the task on the basis of its duration and dependencies, rather than against a particular date.

Sometimes you need to prevent Microsoft Project from rescheduling a task away from a key date. For example, imagine you are managing the delivery of a conference. The date of the conference is likely to have been booked for months and is probably immovable. In this instance you might set a ‘Must start on’ project constraint for the date of the conference.

Assuming ‘Conference day’ has other tasks linked to it (it should), Project will warn you that a constraint might cause a future scheduling conflict.

That is fine because if one of the tasks linked to the Conference day takes longer than planned then we need to know if it will conflict with the Conference start date. Let say that Arranging the AV equipment was planned to take 2 days, but we find that actually it will take 6 days. If we increase the duration to 6 days Microsoft Project will warn us that there is a scheduling conflict (see below).

So Project Constraints can be useful and have a valid part to play in project planning. However, they can also be created by mistake with dangerous knock on effects. In part 2 see how accidentally setting constraints can impact your project plan.

Project Constraints part 2 - common mistakes.

Read more guides on using Microsoft Project

• Constraints part 1 - How to use Microsoft Project constraints
• Constraints part 2 - Common mistakes in using constraints
• Create constraints - How to create project constraints
• Critical Path - Viewing the Critical Path - video tutorial
• Filters - How to filter your plan by certain tasks or resources
• Filters - How to create a custom filter in Microsoft Project
• Highlight tasks - This step by step guide shows how to highlight particular tasks in Microsoft Project.
• Hyperlinks - How to create hyperlinks in Microsoft Project
• Outlook tasks - How to import Outlook tasks into Microsoft Project
• How to create a PDF of your project plan - Microsoft Project 2010 to pdf
• Scheduling problems - How to resolve a common scheduling problems in Microsoft Project