Introduction to Planning and Scheduling - Basic Checklist to a Quality Schedule
Planning and the subsequent scheduling form part of the project controls set of critical
tools that facilitate the success of the project as measured in terms of cost, time
Without a plan project success is immediately compromised. It is as if being asked
by a client to climb the Everest and immediately rushing off to accomplish the feat,
without having properly thought about it. And so off we set at the base of the mountain
without a plan, the how to do it: what resources and in what quantities will be needed,
how long will it take – and what will be the rate of travel distance covered, what
will be the mitigation strategies should there be setbacks or unforeseen circumstances,
As can be appreciated from the above example it would be madness to attempt to climb
the Everest without a carefully detailed and well thought out plan first. Yet this
is unfortunately precisely how many project teams go about business only to be later
confused and puzzled as to why the project is suffering cost and time overruns coupled
with quality issues.
So if the plan is the how to do it, then what is the schedule? This is the time scaled
graphical representation of the various activities needed to achieve the project.
Now, while most construction teams will develop a schedule it frequently ends up
dusty and forgotten. At best a document that’ll be reported and casually glanced
at once a month. And there’s good reason for this attitude: those that would benefit
from the use of the schedule as a tool primarily either have no confidence in the
validity of the schedule or the schedule has an inappropriate level of detail.
Below listed are some flags for assessing the quality of a CPM schedule. It is to
be noted the below flags are in some instances subjective. There’s always more than
one way to do anything and scheduling is no exception. Nonetheless this should provide
a good guide to evaluate quickly the quality of a schedule.
1. Incomplete logic. This is the very first thing that should be looked at.
All activities with the exception of the first and last should have a predecessor
and successor. A schedule that has activities without predecessors or successors
is indicative of a poor quality schedule.
2. Convoluted logic. Schedule logic for the most part should be fairly straightforward
and flow harmoniously throughout with preferably finish to start (FS) relationships.
The over use of lags, either positive or negative, signals poor logic, lack of intermediate
defining activities or activities artificially shifted to meet certain dates.
3. Activity durations. Another item to watch out for. Often times one will
encounter schedules with unnaturally long activity durations. Activities where possible
as a rough rule of thumb should be no longer than the reporting period. Schedules
which contain numerous instances of activities with relatively long durations are
indicative of lack of detail. These activities should be broken into smaller activities
with the corresponding logic.
4. Calendar. It’s somewhat amusing in a way to find a schedule, especially
one that’s been used for some time, with either the wrong project calendar altogether
or with some of the activities using incorrectly differing calendars. For example
some activities using a 5 day calendar while others using a 7 day calendar.
5. WBS. Ideally the cost breakdown and schedule breakdown should follow the
same structure. It is important to note though that the schedule will often times
have more detail than the cost breakdown, meaning that there will not be a one to
one relationship between each cost activity and schedule activity. Rather it’ll follow
a one to many relationship. The important thing is that both breakdown structures
at some level are identical.
Attempting to force a cost breakdown directly into a schedule without additional
detail is a bit like fitting a square into a circle. At the same time at some level
higher than activity level it is necessary for both the schedule breakdown and cost
breakdown to be identical, otherwise earned value management becomes difficult if