What is scheduling in project management?


A schedule is a timetable showing the forecast start and finish dates for activities or events within a project, programme or portfolio. 

When a project manager has defined the scope of the project (the work that needs to be completed), understands quality requirements and risks, and has estimates of activity duration's in place, the next step is to put together a schedule (Starting out in PM3).

Definition from APM Body of Knowledge 7th edition  📖

Time scheduling

Time scheduling is a collection of techniques used to develop and present schedules that show when work will be performed. The results of all these techniques are usually presented as activities or bars on a timeline, known as a Gantt chart.

Understanding scheduling involves learning the terminology associated with critical path analysis – the main technique associated with scheduling Starting out in Project Management, 3rd edition 📖

Scheduling comes into project planning and there are principally two types of scheduling: critical path and critical chain.

Critical path

The critical path approach places emphasis on the activities in a project and understanding the shortest time to complete all activities in a logical order. It is a sequence of activities through a precedence network from start to finish, the sum of whose durations determines the overall duration.

Critical path analysis is an activity- based scheduling technique that determines the overall duration of the identified work based on estimates and logical dependencies.

It is the method of determining the critical path. Critical path analysis is almost exclusively performed using desktop scheduling software, although it is a key skill for project professionals to understand how this is done so they can verify that the project schedule is built on complete and defensible logic.

The purpose of a project manager understanding a project’s critical path(s) is to be able to focus effort in managing the activities that lie on it with the knowledge that if all of them complete on time, and if there is no slippage on other activities that exceeds the total float, the whole project will finish on time.

Critical chain

The critical chain is resource based approach to scheduling, useful when time is critical. It is derived from the critical path that protects critical chains of activities with buffers. The critical chain approach attempts to keep resources at a constant utilisation, avoiding common working practices such as:

  • multitasking between activities;
  • not starting planned work at the earliest start date and committing time until it is finished.

Both these practices result in any float (time contingency) in the estimate being lost to the overall project.

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APM Body of Knowledge 7th edition

You can learn more about scheduling in chapter four of the APM Body of Knowledge 7th edition.

The APM Body of Knowledge 7th edition is a foundational resource providing the concepts, functions and activities that make up professional project management. It reflects the developing profession, recognising project-based working at all levels, and across all sectors for influencers, decision makers, project professionals and their teams.

The seventh edition continues in the spirit of previous editions, collaborating with the project community to create a foundation for the successful delivery of projects, programmes and portfolios.

APM Body of Knowledge

Planning, Scheduling, Monitoring and Control

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Related reading

Path dependence and why it is critical for project success    BLOG  
Knowing how to define and manage critical path is accepted as an essential skill for project managers... read more

Project Management - Lessons from a cross-country drive    BLOG  
Introduction to Critical Chain Project Management (CCPM). And if you think this is simply an alternative to critical path and earned-value, you might be interested to learn that it is much more than that...  read more

The importance of adequate scheduling    BLOG  
Creating a project schedule is one of the most important tasks for us project managers at the start of any project... read more

Managing flexibility in your project schedule    BLOG  
Every project should start with a clearly defined schedule showing when certain tasks start and finish, and when milestone stages and the final deliverable are due to be completed ... read more

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