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the Art Of Effective Time Management - MODERN TOOLS FOR EFFECTIVE TIME
MANAGEMENT
PERT/ CPM
In the late 1950's, two project
management tools viz. CPM (CRITICAL PATH METHOD) and PERT (Project Evaluation
and Review Technique), took the management world by storm. In retrospect, they
are based on sheer common sense, and are extensions of techniques discussed
earlier in this book aimed at higher efficiency.
CPM: Before we
make a critical path method flow chart, it is important to understand that:
EVENTS are
important check posts, indicating start OR completion of a specific task
ACTIVITY is the
actual performance of a task, and the shortest route between two segmental
events.
START [OR PRECEDING] EVENT……… FINISH [OR SUCCESSOR] EVENT
To make a CPM chart: -
STEP 1: List out all
activities
STEP 2: Rearrange them in
logical (flow) sequence
STEP 3:
Check out all activities, which can be performed simultaneously (i.e.
independent of each other)
STEP 4: Based on past
experience, work out time estimates for each activity.
STEP 5: Draw a CPM flow
diagram
STEP 6: Analyze, identify
critical activities
THE PATH CONNECTING THE CRITICAL
ACTIVITIES IS CALLED THE CRITICAL PATH.
CPM is a powerful tool to
optimize use of time, and can be applied to any project, personal or corporate.
Utilized effectively, it is capable of yielding great results.
PERT [Program
Evaluation Review Technique]
First developed by the US Navy
for their Polaris missile development program. PERT basically consists of four
stages:
1.
List out all events
2.
Arrange them in logical sequence
3.
Have experts give time estimates
4.
Develop PERT flow diagram
PERT differs from CPM to the extent that in PERT, we are in
uncharted waters and have little experience to fall back or so far as time
estimates are concerned. Major variations in time estimates are the
distinguishing factor, as explained below:
In estimating time for each activity, three variables are taken into account:
OPTIMISTIC TIME : minimum possible time estimate
MOST LIKELY TIME :
most realistic choice
PESSIMISTIC TIME
:
maximum possible time estimate
The mean of the above three is compounded/used, as follows:
Te = a+4m+b [note the weight age given to ‘most
likely time']
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where: Te is expected time, a is optimistic time etc. etc.
The time estimates so worked out are entered in the PERT flow chart at their
appropriate places (activity lines). Thus, a simple PERT will, at first glance,
appear identical to a CPM.
VARIANCE: Since variance in time estimates is the major
distinguishing hallmark of PERT, and since wider the variance, greater the
uncertainty, variance can be calculated
when absolutely necessary,
but it would fall outside the scope of this book.
The PERT NETWORK should be regularly updated as per
progress of the project
The
advantages of PERT are that it encourages us to divide our complex
project into small specific tasks which are easy to visualize as individual
tasks and hence can be accomplished without stress.
Some
other advantages of using PERT are:
1.
Clear objectives
2.
Helps in task analysis (divides goal into different stages)
3.
Time estimates to compare performance
4.
Sequencing activities
5.
Feedback to institute corrective actions
6.
Monitoring of activities on the critical path
7.
Increased efficiency
8.
Motivation to achieve targets
9.
Adherence to time schedules
10.
Effective control over activities
To sum up, both CPM and PERT help us to reorganize our
thoughts and activities in a logical manner, and represent them graphically as a
visual aid to effective monitoring. They help us to peep into the future,
anticipate pitfalls and bottlenecks and take pre-emptive measures, saving
valuable time.
