Tuesday, February 1, 2022

When A comes before B

When A comes before B
If you understand the nature of A and that of B, and if starting B depends on A, then getting A done before B sounds easy, but sometimes it makes you wonder!
  • Is there a preamble to B that should be done before A is completed?
  • Are the resources for A and B in conflict or not available; such could affect the "preamble" activity.
  • Can B really start after A, or are there other dependencies on the start of B?
  • Do I really want B to start, or do I want to pause and start C somewhere else? 
  • If I start B, immediately after A, have I introduced unnecessary risk or other impacts?

And, there's this:

Schedule depends on sequence
So, if you're thinking about sequencing, you're probably also thinking about schedule: if I plan for "this sequence", how long is it going to take?

Or, the other way around: if you are working on a schedule, you have to get the sequence down first.

Scope is what you sequence, but ...
It seems obvious, but it's worth saying: you have to know what you are going to do. To wit: you can't sequence that which you don't know about. 

And furthermore, even then there may be sequencing errors that you discover once you understand the full extent of the scope. Leave some slack for the unknown!

BUT ... Sequencing value-add to the business may be the ultimate sequence determination. Taking care of the business may be your job-one. If you can, choose sequence in favor of the business!

Scheduling tools
Scheduling tools, like the ubiquitous MSProject, are a good planning tools for sequencing. You can work in the Gantt-chart mode and sketch out the big picture pretty rapidly, setting up key milestones as schedule goals. You need not use the precedence mode at all.

However, there is a bridge too far: 
If  you plan in too much detail, many of these tools are way too tedious to use for maintenance of the schedule once the project is under way. 
As a practical matter there will be "micro-dependencies" that crop up, which are worked in real time; micro-loops for feedback and checking results against the evolving construction baseline, etc. that are way too expensive to schedule, status, and maintain as they change.

Milestone focus
My advice: at the PMO level focus on the major sequences that drive toward value-add milestones.

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