Software Design Description Practise

Question

How many people actually write an SDD document before writing a single line of code?

How do you handle large CSCI's?

What standard do you use for SDD content?

What tailoring have you done?

Answer 1

Most big software companies have their own practices. For example Motorola has detailed documentation for every aspect of software development process. There are standard templates for each type of documents. Having strict standards allows effectively maintain huge number of documents and integrate it with different tools. Each document obtains tracking number from special document-tracking system. They even have system (last time I seen it was in stage of early development) for automatically requirements tracking - you can say which line of code relate to given requirement\design guideline.

Answer 2

I certainly have. Historically and on recent projects.
Years ago I worked in organisations where templates were everything. Then I worked other places where the templates were looser or non-existent or didn't fit the projects I was working on.
Now the content of the software design is pretty much governed by what I need to describe to get the idea across to the audience.
"before writing a single line of code" there wouldn't be a a lot of detail. The documents I produce before I start coding are meant to get the idea of what we need to build across to the affected teams and senior management so they introduce high level architecture, functionality, technologies, risks and scope. Those last two are really important. The rest is to show other teams where you need to interface with them and to leave managers with a lingering notion that cool stuff is happening.

Answer 3

I would suppose that most people who write SDD documents and use terminology like CSCI have to be using a specific software development methodology and most likely are working for some serious government customer. They usually tend to take their preparations quite seriously and the documents are ready and approved before any development starts.

In an Agile process the development and the design document could be developed in parallel. It means that there will be plenty of refactoring to be done but it usually delivers very good results in the end.

In more formal processes (like RUP) a SAD document is mostly created during the elaboration/prototyping phase based on the team research.