The triple constraints triangle (below) is used to show the tensions a project needs to balance when meeting its objectives. Normally set at the beginning of the project, a scope change in any one dimension will have an effect on at least one other dimension e.g. a reduction in time can increase costs or reduce quality. This straightforward approach helps explain the challenges a project can face.
Now individual scope decisions are always highly specific, but I have seen a clear preference across stakeholders in the priority & importance they place on these constraints.
This preference comes across in how they implicitly judge the success of the project. For example a stakeholder whose overriding belief that Time is the key constraint will typically focus on the project schedule and question what’s stopping the delivery and the blockages. The Cost & Quality constraints are less frequently questioned. Understanding this stakeholder preference helps design communications to fit their needs.
In a more radical example leadership teams can push one of the constraints to an extreme, e.g. Cost can become the “only” consideration when things turn bad. This focus on delivering the single constraint impacts the other two and can cause unintended consequences such as low satisfaction scores.
I thought you could carve-up the constraints into the “Voice of” framework so when implementing an improvement project put the Cost & Time constraints into VoB and the Quality into VoC, but I have found this difficult to explain and did not add much value. Anyone with better insight here please advise.