The engagement model determines the basis for cooperation between a client and a vendor. For example, in software development, it defines the most mission-critical aspects: how the project will evolve (in a linear or flexible way), how the team will be assembled (hand-picked by the client to work exclusively on the project or assigned by the vendor), how the payments will be made (in a fixed bid, monthly, weekly, etc.). From our experience, a wisely selected engagement model can increase the chances of project success by 50%. If you choose the wrong one, it can create obstacles that the project will never be able to overcome and recover from.