I am not much of an expert when it comes to business or economics. Of course this will not stop me from writing about it and giving my current understanding of the matter and how it affects design. For instance, take the diagrams known as the time management triangles. Time management triangles intend to show all the factors involved in completing a given project and how they affect one another.
One popular triangle gives the three factors as fast, good, and cheap. You are then directed to “pick any two”. The implication is that all three of these qualities cannot exist in the same project. Basically, this is the project manager’s snarky way of telling the client, “dude, you can’t have your cake and eat it too”. If you want it good and fast, it cannot be cheap. If you want it good and cheap, it cannot be fast. If you want it fast and cheap, it cannot be good.
Although I understand the gist of this particular time management triangle, I think it is poorly constructed. This is a false trichotomy. For example, projects are often good, slow and expensive, which this triangle either suggests is not possible or does not take into account. The good, fast, cheap triangle says, “if you want this good and fast then you are going to have to pay more”. But good and fast are often at odds with each other. You may pay a gourmet price to have a meal in five minutes, but it will not be a gourmet quality. A gourmet meal requires a certain amount of time to allow proper simmering, care, and so on(I am not a chef, but you get the idea). In the same way, for a certain quality of design, a certain amount of time and care is often required.
Another triangle shows time, cost, and scope as the three factors of a given project. It seems to me that this triangle is more accurately constructed. It shows a proper relation between time and cost that the “pick two” triangle does not show. The more relative time on a project, the more relative cost. The bigger the scope of a project, the more time will be required to complete it. It correctly takes out good as one of the three factors and places quality as the natural byproduct of time, cost, and scope. It does not give a false trichotomy, it simply states three constraints that any project (or human action for that matter) has. Cost is probably the most controversial of the three factors because it is harder to define. But any cost in dollars you do not pass on to the customer you incur yourself with time and scope.