Project Management - Time Estimates and Planning
Accurate time estimation is a skill essential for good project
management. It is important to get time estimates right for two
main reasons:
1. Time estimates drive the setting of deadlines for delivery
and planning of projects, and hence will impact on other peoples
assessment of your reliability and competence as a project
manager.
2. Time estimates often determine the pricing of contracts and
hence the profitability of the contract /project in commercial
terms.
Often people underestimate the amount of time needed to
implement projects. This is true particularly when the project
manager is not familiar with the task to be carried out.
Unexpected events or unscheduled high priority work may not be
taken into account. Project managers also often simply fail to
allow for the full complexity or potential errors and stuff ups,
involved with a project. The 2004-2006 Wembley Stadium project
in London is often used as an example, although there are
countless others of less profile.
Time estimates are important as inputs into other techniques
used to organise and structure all projects. Using good time
estimation techniques may reduce large projects to a series of
smaller projects.
Step 1 - Understand the Project Outcome First you need
to fully understand what it is you need to achieve. (Refer to my
article; Project Management - Begin with the end in mind).
Review the project /task in detail so that there are no
'unknowns'. Some difficult-to-understand, tricky problems that
take the greatest amount of time to solve. The best way to
review the job is to just list all component tasks in full
detail.
Step 2 - Estimate time When you have a detailed list of
all the tasks that you must achieve to complete the project then
you can begin to estimate how long each will take. Make sure
that you also allow time for project management administration,
detailed project, liaison with outside bodies' resources and
authorities, meetings, quality assurance developing supporting
documentation or procedures necessary, and training.
Also make sure that you have allowed time for:
* Other high urgency tasks to be carried out which will have
priority over this one
* Accidents and emergencies
* Internal/external meetings
* Holidays and sickness in key staff/stakeholders
* Contact with other customers, suppliers and contractors.
* Breakdowns in equipment
* Missed deliveries by suppliers
* Interruptions by customers, suppliers, contractors, family,
pets, co- workers etc
* Others priorities and schedules e.g. local government planning
processes
* Quality control rejections etc.
* Unanticipated events (e.g. renovating the bathroom finding
white-ants/termites in the walls)
These factors may significantly lengthen the time and cost
needed to complete a project.
If the accuracy of time estimates is critical, you will find it
effective to develop a systematic approach to including these
factors. If possible, base this on past experience. In the
absence of your own past experience, ask someone who has already
done the task or project to advise what can go wrong; what you
need to plan for; and how long each task took previously.
You can lose a great deal of credibility, and money, by
underestimating the length of time needed to implement a
project. If you underestimate time, not only do you miss
deadlines, you can also put other people under unnecessary
stress.
Step 3 - Plan for it Going Wrong
Finally, allow time for all the expected and unexpected
disruptions and delays to work that will inevitably happen.
Sickness, strikes, materials not available, poor quality work,
bureaucratic bungling etc.