ConstructionPro Week, Volume: 6 - Issue: 33 - 08/18/2017

Subcontractor Schedules Benefit All Parties – Early Participation Key to Success

By Paul Levin, PSP


In the typical construction project, the general contractor (GC) is committed to submitting a baseline schedule to the owner for approval.  Because of the requirement for the baseline to be submitted prior to or within 30 days of the notice to proceed, the submitted baseline will contain either insufficient detail (if the contractor can get away with it) or be put together based upon how the GC’s project manager envisions the way the job will play out.  Savvy GCs will reach out early on and ask their major subs for input before they submit the baseline, but this doesn’t happen often.  It’s time for subcontractors to be more proactive in being involved in schedule development. Surprisingly, everyone wins when they do.


Most subcontractors base their labor estimates on the needs of the project and the production rates they expect to achieve.  They will make assumptions about the number of workers, or crews, that will be needed and over what period of time they will have to be on the job.  The subcontractors also make assumptions about the resources that will be available when they are on site, including power and cranes, for example.  What is done less frequently is to actually plan out explicit dates when they will be on and off the job, the sequence of their planned work, how much space they will have for equipment and materials storage, and other related logistics necessary to complete the work.  


Developing the Project Schedule – the GC Should Take the Lead

Picture a construction contract with 20 subcontractors.  That represents 20 different opinions about how the work will be performed.  Add in the GC, and you have 21 opinions.  Granted, the GC has put the most time and effort into studying the project and determining how it best feels the work should be performed, based on its personal experience, current market conditions and the specifics of the particular project.  In general, the initial schedule put together by the GC is a good starting point for a dialog with the subs.  Indeed, savvy GCs will put a schedule together as early as possible, even prior to submitting a bid, and will invite feedback from the major subs, if not all the subs. Since GCs depend on their subs for the accuracy of their cost estimates and work quality, they should start relying more on the experience of their subs for planning and coordinating the work too.  While most GCs probably realize this, the pressure to create and submit a baseline for approval at the start of the project does not leave the GC much time to have the subs involved. 


Different Approaches for Early Schedule Development

The obvious, thorough approach, if the luxury of time allows, is for the GC to develop a critical path method (CPM) schedule as soon as it learns it’s the low bidder on a competitively bid project.  On negotiated projects, this process should start even earlier.  The first pass of such a schedule should be a “level 2” which would include the major components of the project plus further details, such as the various structures, systems, floors, close-in and commissioning as well as substantial completion and other required contract milestones.  The goal is to obtain feedback and participation of the subcontractors in turning a level 2 schedule into a level 3 schedule ready for submission to the owner as the contract baseline. 


The challenge is providing the subs with a schedule in a format they can understand and work with.  Reading CPM schedules can be confusing, and when the schedule includes hundreds, or even thousands, of activities over a one-to-three-year period or more, it can be quite a chore to understand who’s doing what and when.  The ideal approach is to gather the subs in a room and put the schedule up on a screen.  The GC can explain its thought process in developing the schedule and walk through the schedules for the various subcontractor work packages.  The subs can provide immediate feedback and begin the dialogue of coordination with the other subs.  This process may take several additional sessions before there’s a mutual agreement about what’s optimal for the project and for all the subs.  Often, these sessions help uncover problems and help find more efficient ways of performing the work.  This proves to be a win-win for everyone involved. 


When the CPM schedule coordination meeting is impractical or otherwise unworkable, there are other approaches for the general contractor.  This includes providing the sub with copies of whatever initial schedule it has developed and requesting feedback.  With the ease and convenience of technology, GCs should consider setting up virtual meetings to review the schedules, either individually with each sub, or a teleconference with two or more subs. 


Subcontractors Should be more Proactive

Subcontractors who have not been invited to participate in schedule development should take a more proactive role in being involved in schedule development.  The subcontractor can encourage the GCs to hold schedule coordination meetings and/or unilaterally submit a schedule showing how it plans to perform its work in as much detail as possible.  This approach can take one or more of several different forms, including:


  • Submit a CPM schedule created with a program such as Microsoft Project, Primavera, Asta or Pheonix
  • Submit a bar chart schedule produced by computer (Excel, Visio, MS Word, for example), or even by hand
  • Submit a table of activities, with a start and finish date for each activity


It is not always necessary to have dates for the schedule in the planning stage, particularly in the early stages when the project start date is not yet known.  Instead of start and finish of activities being expressed by explicit dates, they can be expressed by a time scale, such as weeks.  For example, the concrete contractor could provide its proposed schedule showing it can start 90 days after receiving a notice to proceed, that it will take 2 weeks to mobilize on site, 3 weeks to do each of the underground garage floors, and that it will take 15 days to do the ground floor and 12 days to complete each upper level floor.  It could show work for each floor working from north to south, and that it can be off the site 3 weeks after the roof is topped out.  The GC can plug this info into its schedule and also inform the other subs.  With multiple iterations of schedules entered into the GC’s initial plan followed by feedback from the subs, the GC will arrive at a realistic schedule.  If this doesn’t accomplish completion by the contract’s completion date, then the GCs and subs need to get together to figure out where it can most economically shorten the plan’s overall duration.  By using CPM software, the GC can focus on the critical path to identify the most likely candidates to shorten the schedule, and conduct further study and team meetings until the desired results are achieved.



Early schedule development and coordination by all the parties to the contract, including major suppliers such as the curtainwall manufacturer on a high rise, can help produce a more efficient and effective schedule.  A team effort may uncover new means and methods, may shift tasks to earlier or later time periods to take advantage of, or avoid, certain weather conditions, and may identify certain resources that can be better shared by the various trades.  The use of BIM as a coordination tool has become more prevalent in recent years, and by incorporating the schedule with 4D BIM tools, an even higher degree of schedule development can take place.  Finally, with subcontractor input, each party takes more ownership of the work it is to perform and when.  This will help in resolving disputes that may arise if work falls behind schedule.  The parties can analyze the as-build data to understand whether the delay is due to owner actions or to the performance of a particular sub; either a production problem or due to change in sequence of the work, for example.  Identifying the source of such delays early helps reduce delay costs and helps to get the project back on track before it gets worse.         




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