I the beginning of the project, project owner will always ask for the ETA of the project. The word ‘ETA’ is borrowed from the airline business which referred to ‘Estimated Time of Arrival’ of a flight. The ETA of a project means when the project will be completed.
In order to come up the project ETA, we need to start from the time need estimate for individual task by the following means:
1. if it is a brand new task not even done before, we would consult the business unit (it would be the team / line manager) about the time needed for the task
2. otherwise, we can also consult old project documentations and find what it normally take to complete the task as a cross reference
When we gather the information (whichever means #1 or #2 above), we should also look for 3 estimate:
1. Most probable amount of time needed
2. Best Case scenarios
3. Worse Case scenarios like weather and other un-controllable factor like ‘time to debug’
During this process, we would also try to find out how many resources (i.e. people and materials) is need for the tast, e.g. 3 workers and 1 foreman; 4 computer programmers and 1 quality assurance personnels.
With all this information, the work breakdown structure will be ‘3D’ – not just list of task, but also the resources as well the time information associated with individual of them. As a project manager, he/she would feel more solid and confident at this stage towards answering the question – what’s the ‘ETA’ of the project.