Construction Scheduling and Schedule Updating
The need for well developed critical path method ("CPM") schedules has become more pertinent in this downturn. Patricia Galloway, a past president of the American Society of Civil Engineers (ASCE), avers that CPM schedules can greatly increase the probability of completion on time while minimizing the incidence of claims. Her 2006 paper summarizes the findings of her extensive research of the industry's experience of CPM scheduling by means of surveys. Ms. Galloway can boast an impressive number of responses from all industry participants. Of the 429 responses received, 41% pertained to owners, 31% to contractors, 19% each to engineers and construction managers, with the remainder made up of consultants, university staff and students.
Ms. Galloway writes:
"While CPM scheduling has been around since the 1950s and is assumed to be a basic tool that is commonly used on all construction projects, the results of the industry survey demonstrate that CPM scheduling is still not a mandatory requirement nor is it a project control tool which has gained the trust of the industry ..."
Her findings indicate that less than 48% of owners demand CPM schedules for their projects, yet more than 80% of contractor respondents indicated that CPM scheduling enables:
- Improved planning ahead of construction;
- Better scheduling;
- Greater understanding of the project; and
- Improved project control.
Fifty three percent of contractor respondents confirmed that CPM scheduling brings increased control over risk and uncertainty. Regarding disputes, 67% of the total number of respondents verified that CPM scheduling minimizes disputes. Given the palpable benefits of CPM schedules, the slow uptake by owners is baffling. The prudent owner will go against the trend by including an independent bid item for scheduling in its tender documents and giving this discipline the deference it deserves in the contract.
The contractor should be contractually obliged as soon as possible after contract award to develop a fully detailed and realistic, resource loaded construction schedule using quality scheduling software. An effective schedule:
- Incorporates input and has "buy in" of the subtrades and major suppliers;
- Shows all owner responsible activities;
- Plans and monitors construction activity, manpower and cash flow; and
- Includes all changes and additions that affect the schedule activities and impact the project completion date and is capable of producing look-ahead schedules.
Revay is frequently asked to comment on a contractor's position, only to discover that the contractor has failed to save every update as a separate file. Needless to say, without a record of the interim schedules, the contractor is pretty much hamstrung. More commonly, scheduling is ineffectual because activities required to complete the work are absent from the schedule, it contains logic errors, overly optimistic duration estimates have been used, or detailed and timely schedule monitoring is lacking. Even if these particular issues are remedied as work proceeds, the difficulty of determining schedule performance with any degree of accuracy persists.
Schedules, if developed and monitored appropriately, become invaluable if it becomes necessary to prepare a claim.
12. Galloway, P., CPM Scheduling and How the Industry Views Its Use, Cost Engineering: The AACE International Journal of Cost Estimation, Cost / Schedule Control, and Project Management (January 2006).