One of the most popular if time-worn characterisations of projects is the so-called 'iron triangle'. This is usually presented in a diagram with the sides of the triangle labelled 'time', 'cost', 'quality'.
I'm of two minds as to whether this is a useful motif for projects.
On the one hand it is simple, memorable and roughly correct. On the other, it is an oversimplification that omits the principle driver of the three project parameters: the out turn value of the project to its promoter.
The general contention is that to vary any one of the parameters, the others must 'give'. So, to decrease cost, the quality may have to be reduced, or the time extended, because usually to decrease time for a project's completion increases cost. Increase the quality, and you have to perhaps lengthen the project's life or increase the cost, or both.
Within bounds, this makes some sense.
But the terms themselves don't represent the reality of projects: I'd prefer delivery (because we don't manage time, we manage our activity with respect to time to achieve delivery), budget (which should include a buffer for the probability of risk) and performance, which brings together the specified quality and project scope to deliver the required business value (or we could alliterate it into 'price, production and performance'). Changing any of the three will change the value delivered, but sometimes value opportunities can be gained by increases. For example, increase the budget on a retail centre to achieve delivery before Christmas to delivery greater business value.
Max Wideman has some rather complex motifs, but I think that this over-cooks the mix; simplicity is best, but only as a point of departure; and the substitution of the terms I suggest helps, I believe, to clarify their implications; but what should be expressed, rather than implied, is that the result has to always be seen in terms of the business value produced.