Deadly Sins of Construction Scheduling – Part 2: Changes to Original Duration and Duplicated Activity Names

The Deadly Sins of Construction Scheduling series of articles, outline some of the most common errors that I have seen throughout my career as a Scheduler, Schedule Analyst / Reviewer, and Claims Expert. These errors can have a major impact on credibility of the schedule and the overall success of the project.


Changes to Original Duration: The Original or planned duration of an activity should have been calculated based on a number of different variables including but not limited to:

  •   Scope or quantity of work
  •   Number of crew hours estimated to perform the work
  •   Previously established productivity rates

Once the Original Duration is calculated, it should not change unless there has been a change to the scope of work, or the resources (crew) that will be performing the work.


Duplicate Activity Names: Most construction projects contain several sections of repeat work, whether it is similar building floor or another section of road / utility work. When developing a schedule it is common practice to copy and paste sections of activities for similar repeated work and adjust according to scope variations.

A common error that we see is failure to change activity Names for duplicated activities. This may not appear to be a major issue; although, it can cause a number of problems during the update process. Some of the potential problems include:

  •   Incorrectly updating activities due to misidentification of activities within the construction schedule
  •   Confusion among the project team that is reviewing the schedule
  •   Unnecessary referencing different pages of the construction schedule to find which work Area the activity is located in
  •   When summarizing groups of activities into a table or report, it may be difficult to correctly identify the correct work Area

Repeated activities should always have their corresponding work Areas (or abbreviated Area) added to the end of the activity name so there are no exactly Duplicated activity names.