The Big Payoff
A construction project intrinsically progresses from laying the foundation to installing the roof, to painting the walls and in the absence of any control processes something like a building results. To ensure the building is what the owner expected, requirements must be fully communicated and adequate controls put in place to ensure the outcome. Understanding and communicating the thousands of requirements with their interrelated dependencies is an exponential problem and knowing what is critical, what is being delayed, what is causing delay, what the priorities are, becomes an extremely difficult and expensive endeavor.
The essence of CEM is all requirements and control processes, managed by multiple different team members, share a single information model. Its primary responsibility being critical path analysis, float calculation, priority assignment and exception analysis.
CEM’s work items, constraints and dependencies are considered when calculating the critical path of the work. All work items and constraints will have a start date, finish date and float. This means everything in the model is scheduled by default and any dimension or constraint can drive the critical path of the project.
This is probable the single greatest benefit of CEM. Every requirement participates in the critical path analysis as a constraint so as soon as the constraint is identified its float and ultimately its priority is calculated. For example when a request for interpretation (RFI) is scoped and submitted, it by default participates in the critical path analysis so a float value would be known. This automatically communicates the priority of the issue to all parties affected. Every bid, proposal, commitment, change order, submittal, test, inspection etc… has float that is derived from the critical path.
The amount of float becomes the primary focus when determining priority. The lesser the amount of float the greater the priority. The consumption of float is a precursor to delay and allows for a clear understanding of what is causing the delay. CEM enables project management to have the confidence that they fully understand the critical work items and constraints and can plan resources with a higher degree of confidence. They will know immediately if and when a change or unanticipated event will impact the critical path and will be able to marshal the appropriate level of effort to mitigate the overall impact.
Each dimension now has a calculated start and completion date which gives the project team a way of communicating milestones at varying levels of detail. There is no need to have specific activities in the construction schedule to represent them. They are a result of normal management of work items and constraints.
Dependencies between dimensions allow for large segments of work items to be constrained without the need to create explicit work item dependencies. This substantially reduces the overhead expense of managing a complex CPM schedule. For example, a project consists of an occupied core and shell renovation where bathrooms are to be gutted and rebuilt. The owner requires facilities to be available for the tenants of the building. The project team would constrain the space dimension that defines each bathroom in a sequence that ensures work will only be done on a single bathroom at a time. All work items with the bathroom dimension are now implicitly constrained by this sequence. The space as a whole is not considered complete until all work items are complete. A delay in toilet partition delivery, noted by the superintendent, immediately highlights the overall impact to the construction schedule alerting the rest of the team of the problem. Maybe the delay is not significant enough to delay the project as a whole. Or maybe it is the root cause of the owner not being able to move in on time causing liquidated damages and loss of profitability.
Implementation of CEM gives the project team a powerful tool to model the complexities of construction execution that leverages the real time predictive capabilities that are only possible with a unified model.