In theory, we assume that the activity time is the mean time to complete an activity.
In reality, what time does the resource manager give?
Is it the mean time?
Seldom.
Usually if you are asked to provide a time estimate for a task, you will pad the time a little (or a lot).
Let’s say that you missed a deadline and your manager got upset.
Next time, your manager asks you for a deadline, guess how much time you will inflate to complete the task?
𝐓𝐡𝐞 𝐭𝐢𝐦𝐞 𝐛𝐞𝐜𝐨𝐦𝐞𝐬 𝐦𝐨𝐫𝐞 𝐢𝐧𝐟𝐥𝐚𝐭𝐞𝐝 𝐭𝐨 𝐞𝐧𝐬𝐮𝐫𝐞 𝐬𝐮𝐜𝐜𝐞𝐬𝐬𝐟𝐮𝐥 𝐚𝐜𝐭𝐢𝐯𝐢𝐭𝐲 𝐜𝐨𝐦𝐩𝐥𝐞𝐭𝐢𝐨𝐧.
Think about it.
If you give a 50 percent task completion time estimate to your boss , your boss would think you were a poor worker.
What probability of completion time do you give your boss?
– A completion time related to 50 percent, or
– A time related to 95 percent?
What if you finished the work early?
Would you tell the project manager?
You would not tell as his expectation would be that you should be able to complete future tasks in that amount of time.
𝐘𝐨𝐮 𝐠𝐢𝐯𝐞 𝐭𝐡𝐞 𝐩𝐫𝐨𝐣𝐞𝐜𝐭 𝐦𝐚𝐧𝐚𝐠𝐞𝐫 𝐚 95 𝐩𝐞𝐫𝐜𝐞𝐧𝐭 𝐩𝐫𝐨𝐛𝐚𝐛𝐢𝐥𝐢𝐭𝐲 𝐨𝐟 𝐜𝐨𝐦𝐩𝐥𝐞𝐭𝐢𝐨𝐧 𝐭𝐢𝐦𝐞 𝐭𝐨 𝐜𝐨𝐯𝐞𝐫.
You would assume that if the project manager knew you finished early he would assume you provided inflated activity times and then would begin to question the time and costs you provided for other activities.
Remember, the cost of a resource is basis the amount of time used by the resource to complete the job. There is a strong tendency to both:
– expand the time estimates of activities and,
– if the activity is finishes early, not report the early finish.
Do you think the project manager is going to provide the boss a project completion time estimate that he or she is only 50 percent sure of completing?
You only have to be late one time on a major project to learn to pad your project times.
What does the manager then do with your project time estimate? Cut the project time and cost and expect the same specifications. Why?
The project manager started as a resource.
Then worked as a resource manager.
Then worked as a project manager, and is now a general manager. He has practiced and knows the rules of the game.