There is a thought-train in the minimalist movement: Consciously question “Can I live without this <TV, pair of shoes, cell-phone, etc ……..>. It’s not a pre-requisite that you only have <one pair of shoes>, but it’s more a conscious thought process of evaluating whether things are really necessary.
I think a similar thought process can be quite valuable in the project context. The project framework of Scope, Budget, Time and Quality provides the project ‘value system’ against which one evaluates the question ‘Is this really necessary?’ Other ways of framing this are: ‘Is the solution fit for purpose, simple, solid and reliable?’ or ‘Are the actions I’m taking as a PM effective?’ or ‘Where should I focus my time and effort?’ for example.
The larger and more complex a project becomes the easier it is to be overwhelmed by busyness and to-do lists. By asking the question ‘Is this the most efffective <solution/action/way to spend my time> etc ?’ you improve your chances of working on the 20% of tasks that really make a difference to your project and it’s stakeholders.