Planning and Executing Your Project

Time Estimating

Are your goals and activities appropriate for the time available? This a question that has to be answered before all the tasks are broken down into weekly activities. The hardest part of the time management task is assigning the time estimate to the activity. When estimating time you might want to allocate more time than you think will be necessary for your team to to complete each goal. Most teams underestimate how long each task will take. To keep the team on track it is absolutely necessary to review your time management system at your weekly team meeting. In the beginning, you will probably notice a discrepancy between the number of hours the team expected to use in certain tasks and the actual number of hours the team spent. If the team finds that more time is spent in one area than calculated and less in another, this information can be used to plan future experiments efficiently.

Tool - Estimating Activity Time (EAT)

You have some historical data to draw upon for your time estimates. You know how long it has taken each of you individually to prepare for some of the tasks. Establishing the amount of time it will take to collaborate and write a paper, support the oral presentation, run experiments in the laboratory, etc. must rely upon assumptions. These assumptions include, the optimistic completion time, the pessimistic completion time, and the most likely completion time.

Optimistic Completion Times are predicated upon the assumption that all will go according to your action plans. According to Kerzner (1999) this occurs about 1% of the time.

Pessimistic Completion Times are predicated upon the assumption that everything will go wrong. This also occurs about 1% of the time.

Most Likely Completion Times incorporate historical evidence, team members committed time schedules, and your strategic management skills to predict the time. This the time that you feel would most often occur.

You can combine these three times into a single value for expected time by making the assumption that the probability distribution of time required for an activity is expressible as a beta distribution with a standard deviation that is one sixth of the range. (Hiller & Lieberman, 1967). The expected time to do the task can be calculated as:

t_e = expected time
a = optimistic time
b = pessimistic time
m = most likely time

Example

If:

a = 3
b = 7
m = 5 weeks
t = 5 weeks

Adapted from Kerzner H., 1998. Project Management A Systems Approach to Planning, Scheduling, and Control.