Dr. Maryam Mirhadi, PMP, PSP
Project schedules play important roles in coordinating the efforts of project team members and identifying the priorities in performing the work. A project work is decomposed into smaller, more manageable pieces of work once work breakdown structures are prepared. The project schedule is then developed to ensure all responsible parties and team members take each and every step that is needed to achieve time, cost, and scope objectives. But an important question that needs to be answered once a project schedule is prepared is how a project team can ensure the schedule is prepared in an appropriate manner? How can project teams make sure the project schedule is reasonable and contains all necessary elements and logical relationships that the project team needs to successfully implement the project? Schedule constructability reviews are expected to answer such questions. Such reviews aim to build confidence in the project schedule by evaluating it and creating a basis for further improvements. This article aims to define what purposes schedule constructability review intends to serve and how a schedule constructability review is performed.
A schedule constructability review verifies that the schedule under investigation meets and/or exceeds the minimum requirements of preparing project schedules. It aims to assess project schedules to ensure they properly represent the steps that need to be taken in implementing the project and verify the feasibility of the construction plan. Schedule constructability reviews aim to closely examine project schedules and determine if they satisfy the requirements outlined in the project scope of work, and confirm that they meet the needs and expectations of project stakeholders, and satisfy technical and contractual requirements of performing the work.
The Construction Industry Institute (CII) defines constructability as “the optimum use of construction knowledge and experience in planning, design/engineering, procurement, and field operations to achieve overall project objectives.” (Construction Industry Institute, 1986) In a similar way, AACE International defines constructability as a “system (process) for achieving optimum integration of construction knowledge in the construction process, balancing various project and environmental constraints to achieve maximization of project goals and performance.” (AACE International, 2017, p. 23) These definitions can be adopted and be used in the context of assessing project schedules to determine the types of evaluations that need to be performed when a schedule is assessed for constructability. Based on these definitions, it is expected that a schedule constructability review identifies schedule deficiencies such as poor logic, improper duration estimates, omissions, inconsistencies, and conflicts to ensure the schedule is reasonable and sound.
Similar to the way constructability reviews are performed to evaluate construction documents for consistency, clarity, completeness, reasonableness, and feasibility of construction plans, schedule constructability reviews are performed to ensure that a schedule meets the following requirements:
- Project work packages and activities are properly identified
- The schedule is complete and entails all the activities that are needed to successfully implement the scope of work
- Proper logical relationships (including finish-to-start, start-to-start-, start-to-finish, or finish-to-finish relationships along with proper lag and lead values) are used in creating the project network
- An appropriate combination and choosing of activity relationships (including physical, preferential, resource, and safety relationships) have been created to define activity dependencies
- The schedule accounts for the technical and technological constraints of performing the work
- The schedule accounts for site restrictions and physical and space constraints
- The schedule meets proper contractual milestones, identifies all interim and ultimate contractual deliverables, and satisfies time and resource constraints outlined in the contract
- The schedule is clear, reasonable, and complete
- Different sections of the schedule are consistent in terms of the timeline, work priorities, and work sequence
- The schedule accounts for preparation times, material and equipment lead times, and preparatory steps that need to be taken or prerequisite work that needs to be completed prior to the succeeding work elements
Since project schedules are prepared at different levels of detail in different stages of progress, schedule reviews need to be performed periodically to ensure project schedules meet the minimum requirements over the course of a project. Project schedules are progressively elaborated over the project lifecycle. In other words, as new information is obtained and scope is further developed, project schedules evolve into more detailed schedules that reflect an appropriate level of detail for that specific planning cycle. Therefore, project teams need to perform schedule constructability reviews periodically to ensure the schedule remains a reliable tool that is reasonable, well-thought-out, and compliant with the technical and contractual requirements.
References:
AACE International® (2018). Recommended Practice No. 10S-90 Cost Engineering Terminology. Morgantown, WV: AACE International. Retrieved from http://library.aacei.org/terminology/
Construction Industry Institute (CII). Constructability; A Primer, Publication RS3-1 (July), CM, Austin, Texas, 1986.
Note: Our competent experts have been the primary authors of two industry guidelines, entitled AACE International Recommended Practice 91R-16 Schedule Development and 89R-16 Management Summary Schedule. These industry guidelines are two of the key references used by cost engineers and project management professionals. If your firm is looking for experts who can assist in developing project schedules or performing schedule constructability reviews; and would like your schedules to be prepared using the best practices of project planning and scheduling, please contact us for a free consultation session.