Continuing
our comparison between the commonly used Critical Path Method (CPM) and
Critical Chain Project Management (CCPM), in today’s posting we will take a
look at how these two methods manage multiple projects. As you will see, the management methods are
quite different in both their philosophies and methodologies.
If your
company’s business model involves managing multiple projects, then you are
probably experiencing competition for the same resources. When this happens, project
managers have to constantly monitor their projects because heaven knows you can’t
be late on yours. You at least have to be
aware of this competition and then react to it.
The problem is, with CPM you probably don’t have sufficient visibility
of how problems and decisions on how other projects are impacting yours. In a typical multi-project environment,
especially one that utilizes CPM, the bottom line here is that if you want a
project completed on time, then you have to start it as early as possible…right?
You have to push it into the mix early so that it will finish on time. Maybe that’s not the best approach? Let’s take a look at how Critical Chain
approaches multiple projects and how it addresses these interdependencies
within multiple projects.
Most of the CCPM software offerings on the market today provide a
very valuable analysis tool. When new
projects are loaded into most CCPM systems, the software has the ability to
scan all tasks within a project as well as all of the other projects and their
tasks within the system and then develop what is known as the pipeline. Simply
put, the process of pipelining reviews all of the tasks across the full spectrum of
projects and establishes an intrinsic order to which they should be completed. Most of the software packages today then determine
which tasks need to be worked first, then second, and so on across multiple projects.
In
single-project environments the projects are independent and the critical chain
is the constraint for each single project. But in a multi-project environment, the
constraints are actually the heavily loaded resources working on multiple
projects. The multi-project approach of CCPM identifies the most constrained resource
which is the one that will most likely impact the project duration of all
projects. Because of the importance of
these critical resources, they must be protected. So as a protective measure, CCPM staggers or
pipelines the project schedules based upon the project’s priority so as to
protect the throughput of projects within the organization. This staggering or pipelining of projects is often
referred to as project synchronization.
In multi-project
environments the projects are not independent but rather they are interdependent because of this sharing of
common resources. In a CPM environment, projects are scheduled as if they are
independent and consequently it is usually impossible to forecast delays in one
project which will impact the due dates of other projects. CCPM integrates each
project schedule into a Drum or Pipeline schedule with the objective being to
improve the throughput of the entire organization. As I said earlier, one of
the common misconceptions is that if you start projects sooner, they will
finish sooner, but in reality the opposite is true.
What CCPM
accomplishes in a multi-project environment is to remove resource conflicts on
the most constrained resources across all projects within an organization. Because we are able to stagger or synchronize
projects, it is possible and probable that more projects will be completed by
the organization. So by simply staggering
or synchronizing projects across the organization and by avoiding the
temptation to start projects sooner, your organization can maximize your
project throughput.
I have
used both CPM and CCPM, so which one do you think I prefer? If you guessed CCPM, you’re absolutely
correct! This completes the series on
Critical Chain Project Management and I hope you learned from it and enjoyed
it.
In my
next several postings, I’m going to shift gears and talk about a subject that
is in the news seemingly every day…..healthcare. I’m going to be reviewing a book that I
believe will one day be a classic and one that every healthcare professional
should read and re-read. The name of the
book is, Performance Improvement for
Healthcare – Leading Change with Lean, Six Sigma and Constraints Management. It’s written by four authors, Bahadir Inozu,
PH.D., Dan Chauncey, Vickie Kamataris and Charles Mount. I am fortunate enough to work with these
wonderful people at a company called NOVACES.
All of the things that I write about in this blog are important, but
when it comes to the health and well-being of people who have to make life and
death decisions, there’s a whole new level of respect that I have. I hope you enjoy this next series of
postings.
Bob
Sproull
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