Combination
The final stage of development was to add all the elements together into a single project - aAVis. Fortunately I had been doing this in stages throughout the process. The Audio was developed in isolation first, while the gui and graphics were developed in isolation, then combined. The audio was then added to the mix, and finally the presets were finalised.
I prefer to develop this way as I can get the bugs out of the individual components, and then all I have to worry about is them working together. I find by developing them in isolation it means I can concentrate on the elements by themselves, and add them together in a "modular" fashion. Essentially this means I can take these elements and re-use them in later projects, which is a great asset to a programmer who needs to save time.