The book provides a primer on the Theory of Constraints and how it can be applied to project scheduling and management. It shows how using concepts like identifying the critical chain of tasks, adding buffers, and focusing on bottlenecks can help projects stay on time and on budget compared to traditional PERT and Gantt techniques. It also discusses how to effectively manage vendors to protect against delays on the critical path.

1. CRITICAL CHAIN
ELIYAHU GOLDRATt
AZAD İRİZ
EMINE TAŞCI
MERVE ESRA AKKAN
SEVTAP SEVGİLİ
ŞERIFE ÖZGÖÇ

2. THE PURPOSE OF THE BOOK
 To change Goldratt educational systems to better
accommodate the quickly changing world of business.
 The book starts by pointing out the problems with how time
estimates are normally done on projects.
 To provide a primer on the Theory of Constraints and an
example of its implementation in a steel mill.
 To proceed to show how the Theory of Constraints can be
applied to schedule generation, resources constraints and
multiple projects.

3. KEY IDEAS
 An information technology saying: "A project will run
out of time but will never run out of excuses.“
 Top management blames externalities, while project
participants more-honestly place direct blame on
internal politics and management.
 The estimate is judged at an 80% confidence point.
That is, the estimator believes there is an 80% chance
that an activity will be completed within this time.

4. As a summary of book
The main story in the book is about an associate
professor named Rick Silver who is struggling to
make it in the academic world. young business
professor.
He and his Executive MBA class learn
together, using the Socratic method, as they
discover and apply radical new project
management concepts. The principal side
characters are a young task force charged with
dramatically reducing a modem manufacturer’s
time-to-market cycle. He is a very good teacher, but
he wants tenure and is in need of publications. His
area is project management and he wants the
articles to make a difference in this field. The fact is
that the theories applied to project management
are not effective and projects are running late at

5.  Think Tank:A group  Budget Overruns:
or an institution The amount by which
organized for intensive
research and solving of the actual cost of a
problems, especially in project exceeds its
the areas of budget. While this
technology, social or does not necessarily
political strategy guarantee that the
project will fail, it does
make it more difficult
to succeed. This is
also called cost
overrun or budget
overrun.

6.  Time Overruns:
Time overruns occur
when projects or tasks
within a project is not
completed by the time
the project plan
specifies. This can
occur when materials
to complete a project
are back ordered and
work cannot be
completed until the
materials arrive.

7.  Bell Curved:"Bell
Curve" is the popular
name for Normal
Distribution (also
called Gaussian
distribution). It is
often called the bell
curve because the
graph of its
probability density
resembles a bell. It
can be used to
measure anything.

8.  PERT and Gantt techniques
PERT is a statistical
tool, used in project
management, that is
designed to analyze
and represent the
tasks involved in
completing a given
Project, especially
the time needed to
complete each
task, and to identify
the minimum time
needed to complete
the total Project.

9.  Critical Path
is defined as the
longest chain of
dependent steps
(longest in time)
and it determines
the time it will take
to finish the
Project.Any delay
on the critical path
will delay the
completion of the

10.  Gantt Charts
unlike PERT
Diagrams, involve
decisions,the
decision of the
planner when to start
each path.Somebody
of them chose the
late start for picking
the vendors while the
other one has
chosen the early
start.

11.  THEORY OF CONSTRAINTs( TOC )
At first,it was related to
production scheduling.
Then it became a banner to
attack “product cost”
methods,then marketing.
Lately ,it seems TOC is
more connected with
methods to remove friction
between people.

12. THEORY OF CONSTRAINTS( TOC )
 TOC is a blend of three
different breakthroughs :
First one,as we all
suspected,is that TOC is
actually a new
management philosophy
like ,TQM,JIT,Re-
enginnering,the learning
organization.. Second
one;is the research
methods it introduces.
Third one, the one TOC is
known for the most,its
broad spectrum of robust
applications.

13.  Identify the system’s
constraints as
physical,like a
bottleneck,type of
resource that does not
have enough capacity to
meet the demand.In that
case, strengthening the
weakest link will mean to
help the bottleneck to
do more.There are two
different ways to
strenghten a bottleneck.
One is simply add more
capacity,by hiring more
people or buying more
machines

14.  Triggering the
student
syndrome in the
resource assigned
to the task - they
have more than
enough time to do
the task, therefore
they start the task
late using up all the
safety.

15. The Evaporating Cloud
 is suited to finding a
solution to conflict
between two parties or
two points of view. The
method requires the
participants to find 'win-
win' solutions because it
emphasizes that both
parties are trying to
reach the same ultimate
goal.

16. W-W
When you win and
the other person
wins, instead of
one winning and
the other
losing, then
everybody is
happy and the
relationship gets
stronger as a
bonus.

17. BUFFERS
The identification and insertion of buffers:
 project buffer
 feeding buffers
 resource buffers

18. PROJECT BUFFER
 It is inserted at the end of the project
network between the last task and the
completion date.

19. PROJECT BUFFER
• Any delays on the longest chain of
dependant tasks will consume some
of the buffer but will leave the
completion date unchanged and so
protect the project.
• The project buffer is typically
recommended to be half the size of
the safety time taken out, resulting in
a project that is planned to be 75% of
a “traditional” project network.

20. FEEDING BUFFERS
• The safety time on the end of the
critical chain is called the project
buffer.

21. FEEDING BUFFERS
• Delays on paths of tasks feeding into the longest
chain can impact the project by delaying a
subsequent task on the Critical Chain.
• To protect against this, feeding buffers are inserted
between the last task on a feeding path and the
Critical Chain. The feeding buffer is typically
recommended to be half the size of the safety time
taken out of the feeding path.

22. RESOURCE BUFFERS
 Resource buffers can be set alongside of
the Critical Chain to ensure that the
appropriate people and skills are available
to work on the Critical Chain tasks as
soon as needed.
 The safety time should be large enough to
insure the resource has at least a 50%
chance of finishing the specific tasks on
time.This safety time is called a resource
buffer.

23. VENDOR MANAGEMENT
 The abstractions of project
management are instantiated by having
portions of the project supplied by
other firms. That is, the simple metrics
of "minimize cost," and "deliver by this
date" may be implicit for internal
teams, but they have to be explicit for
vendors, and there is less opportunity
for fine tuning, and more motivation
for protection.

24. VENDOR MANAGEMENT
 The importance of schedule, and ways to improve
it, can be explored by negotiating tradeoffs
between it and cost.
• What cost incentives for early delivery
will they respond to?
• What cost penalties for late delivery will they
accept? More importantly, what penalties
should we be seeking to imposeto capture our
own opportunity costs and the expenses of a
• slip?
schedule Small delays can create big impacts on
profitability, improvements in delivery
schedule will often be worth a premium.
But focus this effort where it matters - in
the critical path, and the critical chain
dependencies within it.