project management - Boehm’s Model - Explanation -

I'm reading through "mythical man-month" and in the end the update of the 20th anniversary edition is a little bit Speaking about the model of Bohem and the project's efforts to flourish in human-months, the optimum time for delivery on the basis of efforts.

His statement, while discussing Bohem's model, is:

The result convincingly is that the trade between men and months is far off from linear It is believed that Man-Month is actually mythological as a measure of productivity. Specifically, he finds: [16]

• The cost for the first shipments is maximum time-limit, T = 2.5 mm ^1/3 i.e. in months The optimum time goes in the form of cube roots of expected efforts in humans-months, figures obtained from the estimation of size and other factors in its model. The optimal staffing curve is a result.

• The cost curve gradually increases because the schematic program becomes longer than the optimum, people with more time take more time.

• The cost curve rises rapidly due to the scheduled schedule being less than optimal

• Hardly any projects will succeed in less than 3/4 of the maximum schedule of calculation Whether the number of people is applicable. This quote gives the resultant results the software manager offers concrete ammunition when high management is demanding impossible schedule commitments

I am having difficulty implementing this statement practically, I wonder Does anyone have any insight on how this software will inform the estimates? I am trying to explain the predicted formula as it has been here:

It seems that, for a project with the work of a man, a cost-optimal time-to-time - Disbursement 2.5 months This makes sense, however, if you believe that there is a project with 5 men's work, then the conspiracy tells that the price-optimal time-to-quote is 4 months!

Does it suggest that more manpower should be allocated for distribution within this time, or the estimate is huge?

In addition, how can you estimate the optimal employee level from this model? Thanks

There is no need to take it on blind faith with any model, especially when the model actually Easy to test in:

  Try to opt in DM Opt. Average. Team Size 1 2.5 0.4 2 3.1 0.6 3 3.6 0.8 4 4.0 1.0 5 4.3 1.2 6 4.5 1.3 7 4.8 1.5 8 5.0 1.6 9 5.2 1.7 10 5.4 1.9 20 6.8 2. 9 30 7.8 3. 9 40 8.5 4.7 50 9.2 5.4 60 9.8 6.1 70 10.3 6.8 80 10.8 7.4 90 11.2 8.0 100 11.6 8.6 200 14.6 13.7 300 16.7 17.9 400 18.4 21.7 500 19.8 25.2 600 21.1 28.5 700 22.2 31.5 800 23.2 34.5 900 24.1 37.3 1000 25.0 40.0  

> As far as I can see for software development, the optimum data produced by the jackets model upto 10 person-months of business environment (in projects running in non-software companies), specific periods and Size of the cream do not appear.

More than 20 man-months of project figures are more reliable, especially where efforts are tightly coupled.

As a result, I do not want to use the formula for anything, for a period of more than 20 man-months projects in the period, the quick sequence of the guest. For a little less than a quick planning session, you will get a more accurate and reliable result.