Project Schedule Development
Planning the Timing and Sequence of Project Activities
Schedules specify the sequence of project tasks.
Can you imagine starting a long car trip to an
unfamiliar destination without a map or navigation system? You're
pretty sure you have to make some turns here and there, but you
have no idea when or where, or how long it will take to get there.
You may arrive eventually, but you run the risk of getting lost,
and feeling frustrated, along the way.
Essentially, driving without any idea of how you're going to get
there is the same as working on a project without a schedule. No
matter the size or scope of your project, the schedule is a key
part of project management. The schedule tells you when each
activity should be done, what has already been completed, and the
sequence in which things need to be finished.
Luckily, drivers have fairly accurate tools they can use.
Scheduling, on the other hand, is not an exact process. It's part estimation, part prediction, and part 'educated guessing.'
Because of the uncertainty involved, the schedule is reviewed
regularly, and it is often revised while the project is in
progress. It continues to develop as the project moves forward,
changes arise, risks come and go, and new risks are identified.
The schedule essentially transforms the project from a vision to a
Schedules also help you do the following:
- They provide a basis for you to monitor and control project
- They help you determine how best to allocate resources so you
can achieve the project goal.
- They help you assess how time delays will impact the project.
- You can figure out where excess resources are available to
allocate to other projects.
- They provide a basis to help you track project progress.
With that in mind, what's the best way of building an accurate and
effective schedule for your next project?
Project managers have a variety of tools to develop a project
schedule – from the relatively simple process of action planning for small projects, to use of Gantt Charts and Network Analysis
for large projects. Here, we outline the key tools you will need
for schedule development.
You need several types of inputs to create a project schedule:
- Personal and project calendars – Understanding working days,
shifts, and resource availability is critical to completing a
- Description of project scope – From this, you can determine key
start and end dates, major assumptions behind the plan, and key
constraints and restrictions. You can also include stakeholder
expectations, which will often determine project milestones.
- Project risks – You need to understand these to make sure
there's enough extra time to deal with identified risks – and with
unidentified risks (risks are identified with thorough Risk
- Lists of activities and resource requirements – Again, it's
important to determine if there are other constraints to consider
when developing the schedule. Understanding the resource
capabilities and experience you have available – as well as
company holidays and staff vacations – will affect the schedule.
A project manager should be aware of deadlines and resource
availability issues that may make the schedule less flexible.
Here are some tools and techniques for combining these inputs to
develop the schedule:
- Schedule Network Analysis – This is a graphic representation of
the project's activities, the time it takes to complete them, and
the sequence in which they must be done. Project management
software is typically used to create these analyses – Gantt charts and PERT Charts are common formats.
- Critical Path Analysis – This is the process of looking at all
of the activities that must be completed, and calculating the
'best line' – or critical path – to take so that you'll complete
the project in the minimum amount of time. The method calculates
the earliest and latest possible start and finish times for
project activities, and it estimates the dependencies among them
to create a schedule of critical activities and dates. Learn more
about Critical Path Analysis.
- Schedule Compression – This tool helps shorten the total
duration of a project by decreasing the time allotted for certain
activities. It's done so that you can meet time constraints, and
still keep the original scope of the project. You can use two
- Crashing – This is where you assign more resources to an
activity, thus decreasing the time it takes to complete it. This
is based on the assumption that the time you save will offset the
added resource costs.
- Fast-Tracking – This involves rearranging activities to allow
more parallel work. This means that things you would normally do
one after another are now done at the same time. However, do bear
in mind that this approach increases the risk that you'll miss
things, or fail to address changes.
Use of Project Stages:
One of the biggest reasons that projects
over-run is that the 'final' polishing and error-correction
takes very much longer than anticipated. In this way,
projects can seem to be '80% complete' for 80% of the time!
What's worse, these projects can seem to be on schedule
until, all of a sudden, they over-run radically.
A good way of avoiding this is to
schedule projects in distinct stages, where final quality,
finished components are delivered at the end of each stage.
This way, quality problems can be identified early on, and
rectified before they seriously threaten the project
Once you have outlined the basic schedule, you need to review it
to make sure that the timing for each activity is aligned with the
necessary resources. Here are tools commonly used to do this:
- 'What if' scenario analysis – This method compares and measures
the effects of different scenarios on a project. You use
simulations to determine the effects of various adverse, or
harmful, assumptions – such as resources not being available on
time, or delays in other areas of the project. You can then
measure and plan for the risks posed in these scenarios.
- Resource leveling – Here, you rearrange the sequence of
activities to address the possibility of unavailable resources,
and to make sure that excessive demand is not put on resources at
any point in time. If resources are available only in limited
quantities, then you change the timing of activities so that the
most critical activities have enough resources.
- Critical chain method – This also addresses resource
availability. You plan activities using their latest possible
start and finish dates. This adds extra time between activities,
which you can then use to manage work disruptions.
- Risk multipliers – Risk is inevitable, so you need to prepare
for its impact. Adding extra time to high-risk activities is one
strategy. Another is to add a time multiplier to certain tasks or
certain resources to offset overly optimistic time estimation.
After the initial schedule has been reviewed, and adjustments
made, it's a good idea to have other members of the team review it
as well. Include people who will be doing the work – their
insights and assumptions are likely to be particularly accurate
Scheduling aims to predict the future, and it has to consider many
uncertainties and assumptions. As a result, many people believe
it's more of an art than a science.
But whether you're planning a team retreat, or leading a
multimillion-dollar IT project, the schedule is a critical part of
your efforts. It identifies and organizes project tasks into a
sequence of events that create the project management plan.
A variety of inputs and tools are used in the scheduling process,
all of which are designed to help you understand your resources,
your constraints, and your risks. The end result is a plan that
links events in the best way to complete the project efficiently.
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