Often when a best-value procurement is used for construction services, the schedule is a major factor in the technical evaluation. Specifically, for contracts where advancement of the schedule is one of the primary reasons for selecting the design-build delivery method, the owner’s rationale for requiring the contractor’s proposed work schedule is to examine the proposed approach to executing the work while also ensuring that the contractor demonstrates an understanding of constraints and milestones. This is especially important when there are multiple approaches, or means and methods, that could be used.
Schedule as an element of “best value”: Best value is often a trade-off between higher risk and shorter schedule, and the technical evaluation must consider both. In evaluating the schedule, the owner must be able to conclude that the proposed schedule is credible. Making such a conclusion requires an evaluation of whether the specified constraints (e.g., property availability, work hours, permit restrictions) have been respected, as well as an evaluation of whether the durations are reasonable. For tunnel projects, this means not only the assumptions of TBM procurement, but also the assembly, startup, learning curve, daily production, and tunnel clean-up. Often, the durations of such activities are based upon experience, as modified by project-specific supplier information, and thus are reasonably accurate.
However, it is a rare project that includes only a tunnel. In most cases concrete structures, and in some instances architectural, mechanical, electrical, HVAC, and other systems, must be built to complete the facilities. On large multidisciplinary projects, frequently led by a tunnel contractor, the tunnel is often the major cost element. For these projects, it is not uncommon for proposal schedules to accurately represent the tunnel activities; however, the remaining “finish” activities are then shoe-horned into the schedule to meet the contractstipulated completion dates. In such circumstances, the owner may be happy to see that the bidders can finish the project within the contract time frame, but it would serve the owner better to be told that the contract schedule is not feasible given the constraints. Unfortunately, that rarely happens, particularly when schedule is an element of the best value determination. In such cases, the owner’s objectives aren’t met by the schedule that is submitted as a part of the technical proposal. This practice also serves the parties poorly during construction when they cannot predict or regain the time needed for later activities, resulting in an impossible situation for which responsibility must then be attributed.
Misuse of the Preliminary Schedule: Another frequent requirement is for the technical proposal to include a “preliminary” schedule. The primary purpose for including such a requirement is to be able to monitor the job while the contract baseline schedule is being prepared. Since the baseline schedule is typically integrated into the schedule of values and thus provides the mechanism for payment, the preliminary schedule provides a basis for payment until approval of the baseline. In addition, early activities, such as permitting and initial design work, must be accurately represented and managed to the plan: time lost in the beginning of the job is very expensive to make up later, and time saved in the beginning is the easiest won.
In approving this preliminary schedule, the owner’s primary concern is that the work detailed for the initial part of the job represents sufficient progress so that the baseline schedule will meet contract milestones, including the completion dates. Because the later work is not required to be developed to the same level of detail, the owner has to take a certain amount of this on “faith.” Therein lies the reason for the term of the preliminary schedule to shrink over the years. What used to be a 180-day schedule (six months) has been shortened to 120 days, and sometimes even 90 days (three months). When considering the length of time for preparation, review and approval, these times tend to be fairly short, especially for projects with multiple disciplines. The result is that the time available for preparation of the baseline schedule is not sufficient for developing a detailed plan for the (later) work, or for the baseline schedule to be adequately reviewed by major subcontractors. Unfortunately, the result is frequently a deterioration of quality of the baseline schedule: “You get only the schedule product that the contractor has time to do.”
Factors affecting the quality of the baseline schedule: It is in the best interest of both parties to reach an early agreement on the baseline schedule. The primary purpose of the schedule is to provide a logical sequence of the work that demonstrates how the contractor plans to achieve the contract completion date, that gives the owner some method to periodically monitor progress, and that gives both parties an agreed-upon approach to determining the effect of changes upon the contract time. Unfortunately, this doesn’t always happen, for a number of reasons:
¦ The contractor hasn’t finalised subcontracts for some elements of the work. The bid price must include all elements of the work, but in many cases there are multiple suppliers and subcontractors that may be used to achieve the results. The baseline schedule must include sufficient time for whatever workforce will perform the work. Although it might be preferable for the selected subcontractor to provide input to the baseline schedule, procurement activities may make this infeasible. In such a case the contractor must constrain its procurement by only considering subcontractors that agree to meet the approved baseline schedule. A good contractor will respect this procurement restriction. However, not all contractors will do so faithfully, resulting in a negative impact upon the already-submitted schedule and potentially putting subcontractors at a disadvantage right out of the gate.
¦ The owner assumes that more activities will yield a better schedule. This is not necessarily true. More activities yield more complexity, and a greater likelihood that the actual work will not follow the scheduled plan, thus requiring a schedule revision. The “art” of preparing a schedule is to include enough activities to demonstrate and allow monitoring of the plan, but not so many that the view of the forest is blocked by the trees. Appropriate granularity is also relevant to schedule of values preparation and administration. A particularly well-known example of this is the often specified maximum 20-day activity duration. For tunnel projects, where the “mine tunnel” activity may take many months, it becomes more reasonable to supplement the long “mine tunnel” activity with a linear schedule. This is a muchbetter schedule model for monitoring progress.
¦ The scheduling software no longer fulfils its purpose. The software has become so advanced and the rules for what can and should be done are so arcane, that the schedulers (for both contractor and owner) are more technicians than “construction people.” Although the resultant document may comply with the specifications, the content is frequently garbage. One of the results may be that inconsistencies are not picked up by technicians using Claim Digger as a primary means to analyse updates. Therefore, the schedule submittal may be approved, but it doesn’t represent the planned approach to the work. All of these baseline schedule issues can be fixed. But to do so, owners and contractors need to work together in the spirit of true project partnership to define the required level of detail in the project schedule. This includes allowing modification of the schedule midstream without penalising the contractor if the way to build the job can be optimised. It can also benefit the project if bidders include alternatives if there are different ways to build the job, and include sensitivity analyses. The contract could then be customised to the way the owner and the successful bidder agree the job will be built.
The project schedule should be a tool for contractor and owner to jointly manage and coordinate the job. Without a quality, approved schedule in place, changes cannot be addressed in a manner that is fair and reasonable to both parties. Ideally, the schedule provides enough information that contractor and owner can help each other succeed
