What is the best practice for estimating required time for development of the SDLC phases? [closed]

Question

As a project manager, you are required to organize time so that the project meets a deadline.

Is there some sort of equations to use for estimating how long the development will take?

let's say the database

time = sql storedprocedures * tables manipulated or something similar

Or are you just stuck having to get the experience to get adequate estimations?

Answer 1

There's no set formula out there that I've seen that would really work. Fogbugz has its monte carlo simulator which has somewhat of a concept for this, but really, experience is going to be your best point of reference. Every developer and every project will be different!

Answer 2

As project manager you have to remember that the best you will ever we be able to do on your own is give your best guess as to how long a given project will take. How accurate you are. depends on your experience and the scope of the project.

The only way I know of to get a reasonably accurate estimate that is it to break the project into individual tasks and get the developer who will be doing the actual work to put an estimate on each task. You can then use an evidence based algorithm that takes the estimation accuracy of each developer into account to give you the probability of hitting a given deadline.

If the probability is too low, you have two choices: remove features or move the deadline.

Further reading:

• http://www.joelonsoftware.com/items/2007/10/26.html
• http://www.wordyard.com/2007/10/11/evidence-based-scheduling/
• http://en.wikipedia.org/wiki/Monte_Carlo_method

Answer 3

There will be such a formula as soon as computers can start generating all code themselves. Until then you are stuck with human developers who all have different levels of skill and development speed.