The Impact of GPM on Planning and Scheduling
Transcript below:
Brandies: Our guests today are Daniel Molnar, Project Controls Lead of the Northeast region of Merck Pharmaceuticals and Tim Mather, Chief Technical Officer at PMA Consultants and PMA Technologies. I’m Brandies Dunagan, a social media specialist at i.c.stars.
Today we’re going to discuss the impact of the Graphical Path Method on scheduling and planning.
Brandies: So Dan, can you describe your role at Merck?
Dan: Sure. As project controls lead, I tell everybody it’s a pretty easy job. My job is to tell project managers that they’re over budget and behind schedule. But truly, the division that I work for manages over a billion dollars of capital a year, and our role is to support project management teams in developing their schedules and their budgets and keeping track of the progress of the work.
Brandies: Okay, and since we’re talking about the Graphical Path Method, Tim, can you tell us a little bit about the history of GPM, Netpoint, and a little bit about the founder, Dr. Gui Ponce de Leon, PE, CEO and Managing Principal at PMA Consultants?
Tim: I sure can. So Netpoint is really the outgrowth of the GPM as conceived by Dr. Gui, as we can call him, because the Ponce de Leon PE Lead AP PMP takes too long. Dr. Gui came to the United States from Lima, Peru in the 60s and was the first Ph.D. in Construction Management at the University of Michigan; and his doctoral thesis is on the topic of alter algorithms for the computation of critical path networks. So he’s been thinking about this stuff for a while because I think he got his doctorate in ’72 and activated PMA shortly thereafter.
Our organization has grown over the years. It’s a nationwide project and program consulting firm. We do project controls work. We also do owner’s representation work and expert witnessing when projects go wrong – which we would never have to do for Merck because Dan is in place to manage that.
Brandies: Of course.
Tim: So Dr. Gui conceived of this idea of a different way of calculating the critical path. We started to work on the software maybe in 2006 or 2007 to bring his idea to life, and his idea was really to graphically and gesturally be able to manage a project schedule versus the database driven method that were used in CPM.
Brandies: Okay, and since we’re asking about CPM and the Graphical Path Method versus the Critical Path Method, just so we understand a little bit better about CPM, and we understand this traditional approach to develop project plans- you’ve introduced GPM as the evolution of that approach. Can you talk about some of the weaknesses that Netpoint addresses in CPM?
Tim: Sure. CPM was originally conceived in the 1950s as a method of modeling a schedule in order to create a timeline of a project. Nobody had done that. Prior to that, the state of the art was a Gantt chart. It didn’t have the kind of logical ties for predecessors and successors that you would find in CPM. In order to accomplish that, the developers of CPM used a formula that they called the early date and late date; forward pass and backward pass; and it’s a way of running through the network of activities and calculating what the early start date would be for each activity and then each successor activity, and then on the way back, what the late start date would be for each successor activity. Those late dates and early dates are kind of forced in CPM and the big breakthrough in GPM, although there’s a lot that can be talked about in GPM. But the big breakthrough is that because we don’t use that forward pass and backward pass, we have a kind of different algorithm. We’re able to set activities right on their planned date.
So whenever the planner wants the activity put on the date that’s where it stays. In a typical CPM application if you put an app, say you put an activity on March first, but it’s predecessor activity ends let’s say February third, then CPM is going to move your activity back to February fourth, unless you constrain it. Whereas in GPM, wherever you put the activity that’s where it sits and it just gives the planner so much more control over the way the network develops and it’s a much more intuitive way for non-scheduling experts to look at a plan and to help develop a plan and part of the big difference between GPM and CPM, is that with GPM – with it’s very intuitive and accessible graphics – you can access subject matter experts who normally get kind of confused by a CPM application. They can engage in a GPM planning session in a way that a CPM planning session kind of falls flat.
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