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PROJECTCOSTMANAGEMENT ANDPERFORMANCETRACKINGTECHNIQUES 119Figure 13: Example of critical chain scheduling.be found. In this case, accounting for limited resources
often lengthens the project finish date, which is not most
people’s intent.
Other important concepts related to critical chain
include multitasking and time buffers. Critical chain sche-
duling assumes that resources do not multitask. Some-
one cannot be assigned to two tasks simultaneously
on the same project using critical chain scheduling.
Likewise, critical chain theory suggests that projects be
prioritized so people working on more than one project
at a time know which tasks take priority. Preventing
multitasking avoids resource conflicts and wasted setup
time caused by shifting between multiple tasks over time.
Critical chain scheduling also changes the way most peo-
ple make task duration estimates. People often add a
safety or buffer, which is additional time to complete a
task added to an estimate to account for various factors.
These factors include the negative effects of multitasking,
distractions and interruptions, fear that estimates will be
reduced, Murphy’s Law, and so on. Critical chain schedul-
ing removes buffers from individual tasks and instead cre-
ates a project buffer, which is additional time added before
the project’s due date. Critical chain also protects tasks on
the resource-constrained critical path from being delayed
by using feeding buffers, which are additional time added
before critical path tasks that are preceded by non-critical-
path tasks.
Figure 13 provides an example of a project network di-
agram constructed using critical chain scheduling. Note
that the critical chain accounts for a limited resource, X,
and the schedule includes use of feeding buffers and a
project buffer in the network diagram. The task estimates
in critical chain scheduling should be shorter than tra-
ditional estimates because they do not include their own
buffers. By not having task buffers, there should be less
occurrence of Parkinson’s Law, which states that work ex-
pands to fill the time allowed. The feeding buffers and
project buffers protect the date that really needs to be
met—the project completion date (Goldratt, 1997).TECHNIQUES FOR SHORTENING
A PROJECT SCHEDULE
It is common for stakeholders to want to shorten a pro-
ject schedule estimate. By knowing thecritical path, theproject manager and his or her team can use several dura-
tion compression techniques to shorten the project sched-
ule. One simple technique is to reduce the duration of
activities on the critical path. The manager can shorten
the duration of critical path activities by allocating more
resources to those activities or by changing their scope.
Two other techniques for shortening a project schedule
are crashing and fast tracking.
Crashing is a technique for making cost and sched-
ule trade-offs to obtain the greatest amount of schedule
compression for the least incremental cost. For exam-
ple, suppose one of the items on the critical path for a
project was entering data into a database. If this task
is yet to be done and was originally estimated to take 2
weeks based on the organization providing one part-time
data-entry clerk, the project manager could suggest that
the organization have the clerk work full-time to finish
the task in 1 week instead of 2. This change would not
cost the organization more money, and it could shorten
the project end date by 1 week. By focusing on tasks on
the critical path that could be done more quickly for no
extra cost or a small cost, the project schedule can be
shortened. The main advantage of crashing is shorten-
ing the time it takes to finish a project. The main disad-
vantage of crashing is that it often increases total project
costs.
Another technique for shortening a project schedule
is fast tracking. Fast tracking involves doing activities in
parallel that would normally be done in sequence or in
slightly overlapping time frames. For example, a project
team may have planned not to start any of the cod-
ing for a system until all of the analysis was done. In-
stead, team members could consider starting some cod-
ing activity before all of the analysis is complete. The
main advantage of fast tracking, like crashing, is that
it can shorten the time it takes to finish a project. The
main disadvantage of fast tracking is that it can end up
lengthening the project schedule because starting some
tasks too soon often increases project risk and results in
rework.PROJECT COST MANAGEMENT AND
PERFORMANCE TRACKING
TECHNIQUES
Many information technology projects are never initiated
because information technology professionals do not un-
derstand the importance of knowing basic accounting
and finance principles like net present value analysis, re-
turn on investment, and payback analysis. Likewise, many
projects that are started never finish because of cost man-
agement problems. An important topic and one of the key
tools and techniques for controlling project costs is earned
value management.
Earned value management (EVM) is a project per-
formance measurement technique that integrates scope,
time, and cost data. Given a cost performance baseline,
project managers and their teams can determine how
well the project is meeting scope, time, and cost goals
by entering actual information and then comparing it to
the baseline. A baseline is the original project plan plus