Introduction to Objects from a C++ Perspective

You must first decide what steps you're going to have in your process. It sounds simple (in fact, all of this sounds simple) and yet people often don't make this decision before they start coding. If your plan is "let's jump in and start coding," fine. (Sometimes that's appropriate when you have a well-understood problem). At least agree that this is the plan.

You might also decide at this phase that some additional process structure is necessary, but not the whole nine yards. Understandably enough, some programmers like to work in "vacation mode" in which no structure is imposed on the process of developing their work; "It will be done when it's done". This can be appealing for awhile, but I've found that having a few milestones along the way helps to focus and galvanize your efforts around those milestones instead of being stuck with the single goal of "finish the project". In addition, it divides the project into more bite-sized pieces and makes it seem less threatening (plus the milestones offer more opportunities for celebration).

When I began to study story structure (so that I will someday write a novel) I was initially resistant to the idea of structure, feeling that when I wrote I simply let it flow onto the page. But I later realized that when I write about computers the structure is clear enough so that I don't think much about it. But I still structure my work, albeit only semi-consciously in my head. So even if you think that your plan is to just start coding, you still somehow go through the subsequent phases while asking and answering certain questions.

Any system you build, no matter how complicated, has a fundamental purpose, the business that it's in, the basic need that it satisfies. If you can look past the user interface, the hardware- or system-specific details, the coding algorithms and the efficiency problems, you will eventually find the core of its being, simple and straightforward. Like the so-called high concept from a Hollywood movie, you can describe it in one or two sentences. This pure description is the starting point.

The high concept is quite important because it sets the tone for your project; it's a mission statement. You won't necessarily get it right the first time (you may be in a later phase of the project before it becomes completely clear), but keep trying until it feels right. For example, in an air-traffic control system you may start out with a high concept focused on the system that you're building: "The tower program keeps track of the aircraft". But consider what happens when you shrink the system to a very small airfield; perhaps there's only a human controller or none at all. A more useful model won't concern the solution you're creating as much as it describes the problem: "Aircraft arrive, unload, service and reload, and depart".