In complex situations, it is sometimes difficult to assess where the benefits and where the drawbacks of a project occur. It often happens that a change is positive for the system as a whole (a saving, better service, better public health), but that this is at the expense of one or more parties within the system. When it comes to money, compensation from the collective is sometimes necessary to achieve an acceptable, win-win (or not lose-not lose) situation, where the wallet of one is not filled by that of the other.