1. What is flexibility?

1.1 Definitions

Generally speaking, flexibility is defined as the ability to adapt under the dual constraints of uncertainty and urgency. The definition adopted is the one that comes closest to "dynamic flexibility", in line with the "reactivity" economic model with which many companies have been increasingly confronted since the 1970s. This model is mainly characterized by the exasperation of competition on multiple, simultaneous and potentially contradictory aspects: diversity, quantity, costs, deadlines, quality and services. Companies must therefore manage both uncertainty or unpredictability, and urgency: "We don't know in advance what needs to be done, but we have to do it quickly".

It's important to point out that it's the combination of uncertainty...