I find when I and my friends go on hikes that the longer and more complex the trail the more I study the map. This makes perfect sense. The probability of becoming disoriented when the trail is long and has many junctures and crossroads is greater. Likewise a long and complicated project definitely requires a good map, i.e. schedule. But most hiking trails are already well mapped out, so you do not need to create a map for your hike. Each project, however, is particular. You may have a similar project you can use as a template, but each project is singular in some way and requires the creation of its own individual map (or plan).
Large projects require good maps (or schedules). And because each project is different the project management team must create an Integrated Project Schedule map of the project before execution. Veteran project managers know that development of a quality IPS is a good investment that provides dividends throughout the life of the project.
When you create an IPS schedule it is important to know which stakeholder will most rely on its guidance for position coordinates and direction. Doubtless, the IPS primarily supports the project management team. These are the stakeholders that are actually performing the work. So consider the needs of all stakeholders when creating the IPS, but have a particular focus on the project team.
The Integrated Project Schedule describes the entire project scope, and activities from all required trades are included. Further, activities should be fully linked. The IPS also shows a balance and the links between major project functions: engineering, procurement, construction, and commissioning.
Large projects require more activities and associated relationships, but there is a limit to the number of acceptable activities even for extremely large projects. The number of activities in the IPS should not exceed 2,000. This is the practical limit for management of the IPS. Beyond this number of activities, the schedule becomes too cumbersome and impractical.
You want the IPS to represent the appropriate level of detail. Too many activities providing too much detail is a common misstep on large projects. Both extremes though of too little detail or too much detail can have a negative impact on the schedule.
Schedules shy on details do not have clearly defined project drivers. The IPS must properly identify project drivers. Schedules lacking details also have the following negatives:
- Critical path is not clearly defined.
- Inaccurate resource requirements.
- Imprecise measurements for progress updates.
- Excessive optimism built-in psychological factor.
The typical problem on large projects is too much detail. Again, limit the number of activities on large construction projects to 2000. Projects that have too much detail have the following drawbacks:
- Incorrect relationship logic.
- Mismatch between updates and actual progress.
- Confusion plaguing the decision-making process.
- Excessive required debugging efforts.
The proper level of detail is important. It does not, however, need to be consistent. Include less detail for sub-critical sequences and more detail for critical pathways.
Activity duration is also an important IPS consideration. The ideal is for the longest activity durations to span across two reporting periods. Most projects report progress on a monthly basis. With this in mind, the Defense Contract Management Agency’s (DCMA) 14-Points Assessment recommends limiting the number of long duration activities to no more than 5%. DCMA defines long duration as 44-days, which, again, keeps most activity durations less than two reporting cycles.
The project manager must specify the level of accuracy for IPS activity duration estimates. In this decision the project manager has a choice between challenging durations backed up by a final buffer or loose durations that have no buffer. So the project manager must answer the crucial scheduling question: to buffer or not to buffer? This may depend on the type of contract: lump sum or reimbursable. A buffer would be particularly suitable for a lump sum contract.
Milestones have zero duration, but are important markers along your IPS journey. Milestones serve as helpful guideposts telling you where you’ve been or pointing you to where you’re going. Include milestones to define preconstruction and close-out activities rather than activities tracked with physical progress.
The IPS should also include activity codes to support schedule reporting. Create activity codes to filter and report by function, system, zone, equipment, and responsibility. Project managers should include additional activity codes when applicable.
Summary
So successful projects have helpful Integrated Project Schedule maps to guide navigation, particularly for the project team. The IPS should focus on the interfaces and links between functions. It is also important for the Integrated Project Schedule to have the proper amount of detail. Both too little detail and too much detail are not good.
On extremely large complex projects, limit the number of activities to 2,000 to avoid clutter that breeds confusion. Cap the number of activities that have duration greater than 44-days, approximately two reporting cycles. Another important consideration is the accuracy of duration estimates and whether you want to include a buffer. Milestones are also a fixture on good quality schedules. Define activity codes to support robust schedule reporting.
For a more in-depth study on the IPS read “Advanced Scheduling Handbook for Project Managers” by Jeremie Averous and Thierry Linares.