Assumptions in the Shirokuma case

Here are some interesting questions in the Shirokuma case, which highlight the difficulty of preparing estimates in the absence of hard information.

• The durations of certain tasks in the project have only length in time rather than person-months? does that mean that those taks require the work of the whole group or should we consider the duration units as person-months/weeks? For example, the most problematic so far has been the six months required by the DSG for develpment kits, has that got to be considered as 6 months for the whole group or can it be considered as 1 month if the tasks is undertaken by 6 engineers?

To assume a simple equation between duration and effort is to assume that there are no difficulties associated with working as a team, and that the work is routine. Since this is certainly not the case here, I would be very suspicious of such a plan. Where these estimates have been given, you might feasibly halve the duration by adding staff. However, it's in the nature of development projects to require enough time to make enough mistakes. The quality of the output could suffer (and in reality, frequently does) when development is rushed. A good plan will compensate for this in some way.

The engineer in the case study may have been thinking that a certain number of individuals would collectively spend 6 months on the development. For the purposes of the exercise you may assume a team of three people. Doubling the size of the team might at best reduce this to three or four months, and gains beyond that are unlikely - at least for this project.

• Also, there is no mention of the price of bought in power supplies; which come optionally to making them ourselves, so should we consider buying them in as an unconsiderable option?

Not at all, it's the classic "make or buy" question. Resources and time to support the procurement of the right component will have to be planned for.

• Thirdly, The marketing staff have no salary guideline, so should we guestimate one? and are we required to include healthcare, pension costs etc... on top of the stated pay (usually doubles it, more or less).

Make a guess (similar to the given costs of engineers) and illustrate your costings. Whether the overheads are included or not, the main thing should be that the reader should know the position (and the likely rise if they are to be added later on).