The Guide to Good Practice in the Management of Time in Complex Projects (The Guide) will be published at the end of this year. One of he key messages in The Guide is the need to separate planning from scheduling.
Project planning focuses on creating the project development strategy. It requires experience, vocabulary, communication and imagination and, at its highest level, provides the formula for the logistic strategy for the project construction. Project planning involves decisions concerning:
- the overall strategy of how the work process is to be broken down for control;
- how the control is to be managed;
- what methods are to be used for design, procurement and delivery;
- the strategy for subcontracting and procurement;
- the interface between the various participants;
- the zones of operation and their interface;
- maximising efficiency of the project strategy with respect to cost and time;
- risk and opportunity management;
- the design for the schedule and its reports/communication plan.
Scheduling is a mixture of art and science to create the project manager’s time-allocation tool within the chosen software. It involves the interpretation of the results of project planning to ascertain, amongst other things, the start and finish dates of activities, their sequence and the required resources.
It is not good practice to plan the work whilst attempting to schedule it. Starting to develop the schedule before planning the project is unlikely to produce a satisfactory project-planning solution or an effective schedule.
This is not a new idea! James Kelley and Morgan Walker, the inventors of the Critical Path Method of scheduling in the very first paper published on the subject had the following to say:
A characteristic of contemporary project scheduling is the over-simplification which stems from the inability of unaided human beings to cope with sheer complexity. Even though we know that a detailed plan is necessary, we also know that management need only act when deviations from the plan occur. To resolve this situation we undertook to develop a technique that would be very simple but yet rigorous in application. One of the difficulties in the traditional approach is that planning and scheduling are carried on simultaneously. Our first step was to separate the functions of planning from scheduling.
This is an extract from the paper entitled Critical Path Planning and Scheduling delivered to the Eastern Joint Computer Conference in March 1959, by Kelley and Walker less then 2 years after they had invented CPM. Why is it 50 years later so many planners continue to ignore the wisdom learned from past projects and focus on entering data into computers before they have worked out the optimum way to deliver the project?
For more on the history of scheduling and an abstract of the Kelley and Walker paper see: A Brief History of Scheduling