Why You Should Build a New Project Schedule from Scratch
When it comes to building a new project schedule, you have the option of starting with a blank formatted schedule template or use a copy of an existing schedule from a previous project of similar scope and adapting it to suit.
It is only natural to want a head start in life and using the latter of the two schedule building options might seem a good starting point, but would it be a good thing for a Junior Project Planner/Scheduler? In as much as I understand the time-saving rationale behind editing or adapting an existing fully built schedule for use on a new project, my advice to budding Project Planners/Schedulers is to build schedules from scratch.
While experienced Project Planners/Schedulers can get away with adapting an existing schedule, I think it is bad practice for young and inexperienced Project Planners/Schedulers to do so too. I believe that starting with a blank template is one way to become proficient in scheduling.
Reused Schedules & Inherited Errors
First and foremost, I do not think any 2 projects are the same and therefore one runs the risk of not being 100% compliant with the Project WBS when you use an old schedule, which goes against the fundamental requirement that a project schedule should cover the full project scope of work.
Another key disadvantage is that you end up retaining all the errors in the existing schedule and most times these errors are hard to spot and only become apparent much later. Building a schedule from scratch allows you to avoid inheriting inherent errors in an existing project schedule.
Old project schedules are fraught with not having documentation easily accessible and this usually means there is insufficient understanding of the reasoning behind out-of-sequence activities or unusual resource utilisation when these schedules are adapted for use as new project schedules.
Tough but Rewarding Journey
Building schedules from scratch allows Junior Planners/Schedulers to become conversant with the project execution strategy by going through the installation/construction method statement and/or holding interactive planning workshops with the Project Engineers or Construction team.
And by asking the right questions during these sessions, one can determine when an activity logic relationship is preferential or mandatory something that is otherwise difficult to identify if adopting an existing schedule unless there is documentation to that effect. Aside from determining activity dependencies, these Interactive Planning Workshops are also a good opportunity for identifying resource availability and constraints as well as schedule risks.
A lot of effort goes into building schedules from scratch and because you are physically typing activity descriptions, assigning durations and resources, adding logic relationships between activities, your brain is forced to pay attention to some of what you are typing leading to improved understanding of the project scope and execution.
Another justification for building from scratch is that it creates an opportunity for Planners/Schedulers to properly document and own the Schedule Basis (Schedule Memorandum or Narrative), making it easy for the project team and stakeholders to see assumptions that underpin the schedule.
Finally, when you have built a schedule from scratch, you tend to have the confidence to explain or defend your schedule when questions are asked since you know the schedule like the back of your hand.
I strongly believe that the more you build new project schedules from scratch the better your chances of becoming more proficient in Project Planning/Scheduling and the more likely you will become a Planning/Scheduling Subject Matter Expert (SME) in your sector.
