PERT! The simple technique to make projects go better
Prefer to watch on video? Just click here. 5 mins, with captions.
We’d all like projects to work better in our organisations. Whenever we try to do this, however, it ends up in a template-infested swamp of mediocrity.
Sometimes the smallest things can make a huge difference. Even things you’ve maybe heard about before. So, I’d like to (re)introduce the PERT Chart as a simple technique that can make your projects just go better.
Gantt You Hear Me?
When we talk projects, we’re usually thinking Gantt Charts. These come from an actual person – American Henry Gantt, sometime just before World War I, and they were used by the US Military in that minor skirmish.
They were actually around before that, under the guise of the ‘harmonogram’, coined by Karol Adamiecki from Poland, but as Karol didn’t get the pen to paper quick enough, we today have the ‘Gantt Chart’. Which is a bummer really – wouldn’t you rather bust out the harmonogram? 😊
Just to remind you of the Gantt Chart, here’s one below – time periods along the top, tasks down the side, the bars representing when stuff should happen. And possibly causing an allergic reaction for those of us suffering project overload.
Here’s the thing – they aren’t natural to read for anyone who is not a project manager most of the time. A bit like reading a list of destinations instead of a map – it’s tough to see how it all fits together.
And here’s another thing – Gantt Charts are used to drive due dates. And how do we respond to due dates? By breathing a sigh of relief when the date is not tomorrow, and doing something else! Only to find out when we do start it, that we’re missing something. So…best case scenario is we meet the date. Often-case scenario, we miss it.
So perhaps the Gantt Chart itself is causing all those project deadlines misses? Maybe. At least enough to try a different way.
The PERT Chart
So enter the PERT Chart, which is an acronym for Program Evaluation Review Technique…an expression I find virtually meaningless except for the last word.
Here’s what they look like.
The circle on the right is what ‘Done’ looks like for the project. You can describe the final thing in there. The other circles are tasks or deliverables that need to happen to get to Done. And, working from left to right, we see the order in which they need to happen.
That’s it!
PERTY Good Reasons
What’s so great about this? Four things:
- Everyone can see the whole project at once and how it fits together (the ‘full system’)
- The ‘critical path’ is easily worked out and obvious
- We can build it together to create buy-in
- We avoid the ‘due-date’ trap
Seeing the whole project at once
The PERT chart is a picture worth a thousand words, or a thousand bars on a Gantt Chart. It takes a particular type of mind to naturally understand a Gantt coming out of something like Microsoft Project, or Excel. And we do need these things to calculate resources, budgets and the like.
But for everyone involved to simply see how it fits together….the PERT Chart is the go. It’s the difference between describing how to get somewhere vs drawing a map.
The ‘critical path’.
The critical path is nothing fancier than the longest route through the project. It might not be the official Gary PERT way to do it, but I draw in each circle how long that task will take (there are certain rules I use when I’m setting up what I call the Project Factory™ but that’s for another article). We then simply add up which of these is the longest path.
Lots of people know this, but fewer know what to do with it. The critical path is the equivalent of the slowest machine in a factory, it’s the pacesetter for the whole show. And…just like the slowest machine in the factory, the pace of this line determines the pace of the whole project.
Just like there is no point improving something other than the pacesetting machine, there is no point attempting to speed up any line other than the critical path. Which means to manage the whole project, the project manager now has a clear and obvious focus point.
How is this done practically? Two things:
- Anyone working on the critical path is left alone. Put a big fluffy toy on their desk or something, which means “bother me some other time, I’m on the critical path”
- The project manager asks those working on the critical path, at the end of each day…”how much longer will the task take you”. This can then be compared to the total time originally estimated for the task, so we can see whether we are eating into the project buffer.
And no, this is not called micromanaging. It’s called managing.
Build it together
You can quickly get your team, Division, or Organisation used to getting together to knock up a Gary PERT. You just get in a room, clarify ‘Done’ and ask “what are the things that need to happen or be delivered to get to ‘Done”. Write each of them on a card, write on how long it will take, arrange them into a PERT.
30 minutes for a small project, 90 for a medium, half-day for bigger. Just do it. Schedule another one if you need.
What happens when you do this? More buy-in. Which is a good thing.
Avoid the Due Date trap
The PERT chart exists without dates. Keep it that way, and set up the metaphor of a ‘relay race’ which I first heard of from Rob Newbold and Bill Lynch in their great book The Project Manifesto – which means the job of those on the critical path is to get the baton to the next person in the PERT Chart as soon as they can (with warning).
Remember, due dates encourage leaving things until the last minute. Or making things perfect. None of which matter in a relay race, where the job is to hand on the baton at the ‘good enough’ standard.
And for management of the project overall, put a buffer in at the end. If critical path tasks are going to end up taking longer than estimated in the Gary PERT session…then you’ve eaten into some buffer. And that’s fine…because that’s what it’s there for. And now you know where to manage.
So that’s the PERT Chart. These don’t have to replace Excel or MS Project which are brilliant calculation tools that let you track budget, resource usage, spread resources appropriately so things are realistic…all good stuff. Use them for bigger projects…you need them.
But for visualising the project in a way everyone can picture it….and probably for most of the projects going on in your organisations – a quick PERT Chart pays huge dividends.