step 1 define abstraction criteria.
this can be an easy task or very difficult. a lot of it depends on the particular problem that is being solved. if the problem lends itself to layers then it becomes much simpler to define abstraction layers. the paper listed a chess AI program as an example that lends itself to layers nicely. this step tends to be an interative process. the first try is rarely going to the 100% right.
step 2. deterimene the number of abstraction layers
this step is more art then science. the more systems you work with the easier this step becomes.
step 3 name layers and assign tasks
this step is fairly simple compared to the first two tasks. the author feels this step takes a lot of experence to do correctly. i think the abstraction criteria is done correctly this step should be almost intuitive.
step 4 Specify Services
this is a refinement of step 3. step 3 determines the outline of the layer step 4 defines the inner works of the layer.
step 5 refine the layering process
repeat steps 1 through 4 till each layer is solid.
step 6 define the interface for each layer
once each layer is solidly defined it should be clear what each layer needs so defining an interface should be somewhat simple. the author state that doing this is black box fashion is best and i agree.
step 7 structure individual layers
this step would involve filling in more details of how each individual layer should work. this step can vary from simple to complex depending on how complex the individual layer is.
step 8 specify communications between adjacent layers
this is fairly simple step just a choice in which communication methodology to use. the author suggests 2 common ones. push pull method and callbacks
step 9 Decouple adjacent layers
this is very architecture dependent. it could be simple or very difficult to do
step 10 define an error handling strategy
this is another basic design choice that can vary from architecture to architecture
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