Design top to bottom or bottom to top?

Question

Basically, there are two approaches to developing a system. What are the advantages and disadvantages? When should I use this? Should I combine these approaches? How?

Answer 1

Roughly speaking, from top to bottom comes from decomposing the problem space into sub-tasks, while from bottom to top it comes from organizing parts of the solution space to larger pieces.

To make effective use from top to bottom, you need a very clear understanding of the problem, i.e. have firm demands in hand. To be effective from the bottom up, you need to solve the “standard” problem, whose parts are well known, but where precise assembly may be required for some experiments before you fix it.

You should read Parny’s brilliant paper The rational design process and how to fake it for much more. Answer: use both options if necessary. When everything is ready, do it all (in your specifications, project documentation and user documentation), as if you did everything from top to bottom.

Answer 2

I think your question deserves a long and clear answer. I suggest reading Martin Fowler's old article (cfr. "Is design dead?"), Which discusses relationships regarding avant-garde design and agile methods ( http://martinfowler.com/articles/designDead.html )

My experience is to always have a blue architecture for printing modules, the interaction between the components of the system. Having this project (which in some projects can be at a high level), I begin to develop / develop modules / components. Some of them can also be developed from the bottom up.

Answer 3

You should also take a look at the cake slicing principle from a flexible community. This principle makes you focus on adding business value to the user with each iteration of your application. You are trying to design and implement a vertical slice of your application and deliver it, and then focus on the next fragment, etc.

Here is a link that explains the principle in more detail http://blog.energizedwork.com/2005/05/slicing-cake.html