Hi,
i'm interested in module design (designing, planning or as you say). How do you start modules? I'm on the progress in new module creation, so i can say share my experience So at first i tried to write all different parts in CMS. When i had parts, i detailed them. I write all methods (with input/output) and classes and thought about file structure. After that, i programmed all these parts. Now, when i have my cms with working parts i re-look all parts, added more functionality and started to thought about site layout and blocks. After that i found some mistakes in my cms part and added even more to it.

What did you do? Do you design ALL parts at once? Do you think about all or a half module? Do you just think, but do not mark and start to develop it? What? :) I would like to hear some thoughts about that.

Here's how I do it, but it is only my way of doing things.

Any programming:
1/ functional requirements spec (what it does, not how it does it)
2/ data model required to support the functional requirements
3/ input and output requirements
4/ processing model (how it acheives what it wants.)
5/ object model to support all above

Xoops:
6/ Create list of user side page requirements
7/ create list of admin side page requirements
8/ create module framework (I use my own XBS ModGen module generator for this,) using information collected above
9/ create the object model code
10/ create each page and output to basic page templates
11/ test functionality against 1/ above
12/ refine page templates and re-write, creating supporting css as required
13/ test, test and test again