Summary Table of Differences between Critical Chain Project
and Traditional Project Management
Critical Chain Project
Benefits obtained from CCPM
1. Schedules worst-case task
Schedules average task
do not collect safety time "fudge factors". Risk, stress, and effort
are shared equally amongst all tasks & resources. People start to
think differently than before. "Sacred cow" schedules are avoided.
People can see what's really consuming the elapsed time. Management
can manage, project durations are cut, people can go faster with less
stress. Everybody and every resource are treated fairly & by the same
rules. Ineffective hierarchies are broken down.
2. Protects individual tasks
with safety time.
Protects overall project
completion with buffers.
is not hoarded by individual tasks and people, but shared by everyone.
Safety time is conserved and used most wisely over the entire
project. Focus is placed on what is most important to the customer:
3. Emphasizes task progress.
Emphasizes project progress.
sees the "Big Picture". Micro-management is avoided. Project
Managers have a consistent outlook through the entire project. Events
that slow the project are constantly in the schedule spotlight.
People stay focused on the problems. Problems get
identified more quickly, and get solved sooner.
4. Starts gating tasks ASAP.
Starts gating tasks when
they need to start.
and limited resources are not plugged up with non-critical tasks which
block & slow critical tasks. This is similar to Fire Lanes and sirens
on emergency vehicles. Non-critical traffic stays off the roads until
the emergency vehicles have passed. Use of bottleneck resources is
based on priority, not "first come, first served". Projects get
5. Starts and finishes tasks
at scheduled start and finish times.
Starts tasks as soon as
predecessors are done, finishes tasks as quickly as possible.
managed and implemented like a relay race. The baton always goes
around the track at maximum speed. Runners pace themselves for
hand-offs so the baton never stops nor slows down. If you are
carrying the baton, just finished carrying, or getting ready to carry
it next, your activities are tightly monitored, controlled, and
managed; all others are of lesser priority and have freedom to
self-manage. People focus better, and
projects get done faster and cheaper.
6. Makes resource contention
a PM "fact of life".
resource is identified by CCPM schedule. All users of the critical
resource are identified up-front and conflicts resolved. Project
Managers watch only the critical resource; constantly focusing on
what's important and preventing problems from occurring. Constraints
7. Makes multi-tasking a PM
"fact of life".
Minimizes multi-tasking by
terrible cost of multi-tasking is exposed. All personnel are trained
on "bad multi-tasking". People hunt down & eliminate their own
multi-tasking, multi-tasking forced on them by others, and
multi-tasking done by others. This alone can cut project schedules
elapsed time by up to 40%.
8. Reacts to uncertainty by
changing priorities, expediting, and creating a new schedule.
Manages uncertainty by
monitoring impact of events on buffer consumption.
schedules and their priorities stay consistent. People don't get
confused, nor lost as readily. The impact of one project on all other
projects is minimized. Entire organization stabilizes into busy and
productive status quo activities, rather than chaos. People feel
benefits from CCPM; they are more productive, less frustrated,
involved. Their contributions & efforts matter. Morale climbs.
9. Makes task linkages and
constraints reflect ad hoc or habitual scheduling decisions.
Makes task linkages and
constraints reflect only physical scheduling requirements.
cows" like "we've always done it that way" get challenged. People
innovate. Opportunities are identified automatically. Historical
systems are re-designed & changed to take advantage of theoretical
opportunities; making these opportunities reality. Rate of learning
in the organization & adaptability are maximized. Competitors are
left behind with their old, non-competitive paradigms. You become a
world-leader in your industry.
Traditional Project Management methods usually use task duration
safety factors of 3 to 4. Most of this safety time tends to get
- We use the most probable task durations; typically half as
long as what is traditionally used.
- We accumulate the safety time into a few manageable Buffers that
project managers and Senior management can watch very closely
- We minimize or eliminate the multi-tasking which consumes up to 60%
of the project time
The total project duration is shortened by at least 10%, to
as much as 50%
Reality in Project Schedules
The following image explains how a 3 week duration task grows into a 10
week task duration estimate that get used in traditional project
With CCPM (Critical Chain), the best possible (but fair & realistic)
task estimate of 3 weeks gets used in the schedule. People realize
it's very tight, but possible, and have a healthy (not crippling) level of
Project team members work hard & fast to achieve the goals (fastest
possible project implementation).
The overall CCPM schedule keeps 3 weeks for the task, plus 3 weeks of
safety time (to be shared by this task, as well as all other tasks).
CCPM (Critical Chain) quickly and easily reports who is using up the
safety time, and asks the question, WHY?
Social pressure of the project team causes everybody to conserve
overall safety time, rather than using more than their "fair share" of the
overall safety time.
The end result is the project task gets done on-time and on-budget.
Critical Chain Project Management (CCPM) allows your project
plan to match the reality of how people work.
Classical project management assumes everyone will exactly follow the
formally defined schedule. Reality is adjusted for by the use of
excessive supervision, pressure, expediters, excessive co-ordination
meetings, re-baselining, pleading, scope reduction, feast & famine
activity levels, overtime, etc.
People are not robots who tirelessly do everything right, exactly when
they are supposed to. Not even robots do that! We all know
- People get bored at mundane tasks.
- They get overwhelmed by too much information given too quickly.
- People get nervous & frustrated when everything seems to be
changing, especially when it occurs rapidly or continuously
- People have personal priorities ("pet projects" & private agendas)
- People tend to do what they like doing, before they do what they
have to do.
- Each person does certain tasks very well, and others they shy away from.
- Most people tend to be optimists, and assume things will go better
than they really do.
CCPM doesn't demand people to be "perfect little robots" in
order to work together effectively. Instead, it assumes that people
are human, with strengths and weaknesses.
CCPM supports the people by adding strength where people need
help, and allowing people freedom to create and work in areas where they
CCPM provides the strong structure that people and
organizations need, while permitting the flexibility and individualism
that we all want.
CCPM is simultaneously strong
Simplicity in Project Management
Many of us have designed or planned projects where everything known
about the project, the deliverables, and the people was put into the
Hundreds, if not thousands of related pieces of information are
entered into the system. Small changes occur, resulting in obsolete
data which we don't have the desire, nor the resources to keep
CCPM works on the philosophy that :
It is far better to be
Instead of thousands of tasks and micro-management that traditional
project management methods use, CCPM lets
us define and effectively manage the most complex project with 300 tasks
More tasks and details may give us the illusion
of control, but excessive detail removes our ability to see, decide, and
act effectively & swiftly.
Managers are responsible for producing the deliverables on-time,
within budget, while using the assigned resources.
If a manager knows that a significant problem may soon arrive, they
can take effective preventive actions before the project is
- "Who does What & When" reports so everybody knows what to
- "Fever Charts" and "Buffer Reports" so managers can
see how they have consumed or protected their precious safety time
buffers, and accurately predict when the project will complete.
- Hierarchical resource assignments so that tasks go to the least
specialized resource who is competent at doing that task.
Applications for Project Management
Not all project management software was created the same; especially
in how the implement CCPM.
See PQA's brief overview on the major
project management software.
Free PM System Questionnaire
to build a world-wide database for
an up-coming research paper being developed by PQA, we are collecting
data on the current status of Project Management systems around the
world. To assist this research effort, PQA is making their
Project Management System Survey
available to you free of charge; previously
only available to PQA's clients. Download the form, fill it in,
analyze your results. We ask that you share your results with PQA
in confidence, so as to advance our research into CCPM and Project