Striking a Balance: The Right Level of Detail for a Construction Schedule
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July 29, 2024
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This article from Corporation des Entrepreneurs Généraux du Québec was first published in French in July 2024. The entire article is available at: https://www.cegq.com/fr/details-article-1/trouver-lequilibre-le-niveau-de-detail-adequat-pour-un-echeancier-de-construction
A schedule is an essential planning tool on construction projects, yet preparing one can be a time-consuming and complex task, even for seasoned contractors. An effective schedule must strike a balance between simplicity and providing information that is both clear and relevant. In this article, we present practical resources and recommendations for achieving the appropriate level of detail in a construction schedule.
Industry Recommendations
The Association for the Advancement of Cost Engineering, or AACE, has published two key resources on this topic: RP 37R-06 and RP 61R-10. RP 37R-06 outlines different levels of schedule detail, ranging from level 0 to level 5, and RP61R-10 provides guidance on schedule design.
RP 37R-06 describes schedules levels of detail from a level including only the project start and end dates (level 0) to one with the highest degree of detail (level 5).1 Table 1 summarizes the characteristics of levels 1 to 5.
Table 1 — Schedule Levels of Detail2
| Level | Purpose | Recipient |
|---|---|---|
| 1 | Reflects the main phases and milestones | Project owner |
| 2 | Reflects the main deliverables, phase, and areas | Project directors and sponsors |
| 3 | Shows the links between the various trades, identifies the critical path of the project, and enabling the work to be planned and managed | Project managers, owner representatives, superintendents, and foremen |
| 4 and 5 | Reflect the planning of work packages and the work carried out by subcontractors at different levels of detail (level 5 schedules may be prepared using units of days, hours, or minutes) and are used as a tool for planning the allocation of resources (i.e., manpower, equipment and materials) | Superintendents, formen and subcontractors |
The appropriate level of detail will depend on the nature, complexity, duration, and size of a project. Specific recommendations on the level of detail of schedule activities vary among sources. RP 61R-10 recommends that activity-level detail be based on the frequency of schedule updates.3 A simple and often-used rule of thumb is to limit activity durations to the time interval between the schedule updates. For example, if schedule updates are issued monthly, no single activity should exceed a duration of one month. This rule should be applied with discretion; for quarterly or annual schedule update, an increased level of detail will likely be necessary.
The schedule must show enough detail to enable linking impacts and delays to specific activities while keeping the number of activities manageable. Overly detailed schedules can become too burdensome to update and risk becoming ineffective as planning tools.
Increasing Schedule Detail
When a schedule lacks detail, there are several options for increasing the level of detail in a schedule, two of which are presented below:
- Division of activities by work area: For example, by floor in a building project, or by sections of chainage for road and transit projects. Ensure the links between activities in different areas are maintained.
- Division of activities by type of work: For example, MEP (mechanical, electrical, plumbing) activities can be divided into electrical rough-ins, plumbing rough-ins, etc.
In Summary
The level of detail of a schedule should correspond to the specific needs of the project and the intended recipient. For example, a schedule for planning activities during a shutdown may require 15-minute increments, whereas a schedule presented to senior management might only show the start and end dates for the main phases of the project. These recommendations can therefore serve as a framework for preparing schedules that are both practical and effective. In all cases, if contract documents provide specific requirements for the contents of schedules, at a minimum, these requirements should be met.
Reprinted with permission from Corporation des Entrepreneurs Généraux du Québec.
Footnotes:
1: AACE® International, Schedule Levels of Detail - As Applied in Engineering, Procurement, and Construction, AACE® International Recommended Practice No. 37R-06 (20 March 2010).
2: Id.
3: AACE® International, Schedule Design - As Applied in Engineering, Procurement, and Construction, AACE® International Recommended Practice No. 61R-10 (11 October 2013).
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Published
July 29, 2024
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