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3 construction project metrics every engineer should be using
When starting as an engineer, it can be tricky to figure out the best ways to allocate your time and attention. All projects can get pretty hectic, and if you’re not careful, things slip through the cracks.
As the years progressed, I learned what works and what doesn’t. And one of the things I really nailed down was knowing what metrics to focus on.
If I were to go back to those early days again, I’d know that PPC, Delay Breakdown, and four-week average slippage are the most important metrics for delivering projects and increasing productivity.
Key construction project metrics
Whilst there are a whole bunch of different metrics you could use to try and keep your project on track, I found these to be the most important.
1. PPC (Percent plan complete)
It’s not perfect, the variety of ways people like to measure it is confusing, and supervisors often need a moment to understand what it means. But it’s the best way to measure whether the project delivered what it said it would last week.
The way I liked to approach PPC was to measure the number of planned working days (of scheduled tasks) and compare it to the actual working days performed - measured a week later.
For example, if rebar was going to start on Thursday and finish on a Tuesday in the measured week, there would be three working days (assuming Saturday was a working day).
But if something went wrong and the work actually started Friday, then there would have been two working days.
2 working days / 3 planned days = 0.66 PPC
Repeat this calculation across every planned task in the plan and average.
If you’re unfamiliar with this model, check out our blog on Understanding Percent Plan Complete.
2. Delay Breakdown
In that same scenario, PPC told you that last week was rubbish, and only 20% of the planned work happened. What next?
Often in construction, the story of “why we are late” is a simplified retelling that tries to condense a range of issues into the most understandable (and sometimes politically correct) package.
That story almost always obscures the real reasons, and as a project engineer or manager, you need those reasons to point you at the correct problems to solve.
Tracking each variation, its root cause, and quantum allows you to calculate the delays in the previous week and pivot by delay reason.
3. Four-week Average Slippage
On most projects, engineers will plan four weeks in advance and update weekly. Typically, before the work starts, those plans can be made “aggressive” as a sort of target. As work begins, reality hits, and durations expand.
This is a generalisation, but it’s fair to say that a lot of sites take this approach.
The result is a substantial delay in work planned over the short term that isn’t captured in PPC because it is future work.
Sure, you’ll likely pick this up in four weeks when the master schedule gets updated, but by then, everyone on site is aware of (and working towards) these new cushy dates.
So for me, I found it best to track the end dates of all the tasks in the lookahead plan, measure their slippage (new end date - old end date) and average that across all tasks.
Another handy trick is dividing that number by the average working days in a week to get the measure in week equivalents. If you are above 1.0, your average task is slipping by more than a week per week. That’s a big problem!
My biggest tip to my younger self would be to focus on fewer metrics, report those same metrics consistently, and talk about them constantly with my team.
By focusing on PPC, delay breakdown, and four-week average slippage, you can stay on top of your project and still find time for the million other things you’ve got on your plate.
BTW, if you’re an Aphex user, then all of these metrics are calculated for you automatically.