Win-win term is connected to game theory and it means such game ending when both sides of competition gains something. In such situation there will be two winners and no losers. We can use the same approach when we are trying to define contract between customer and Scrum team. In most cases customers would like to get final project estimation before signing a contract.
There is also second type of agreement, so called time and material. In this type of contract customer pays for time spend by the contractor’s employees to perform the work. Sometimes customers do not like such agreement. In most cases it is matter of trust. But you can try to convince or even encourage your customer to use this type of contract by making it more attractive for both sides. For example customer can commit that he will pay for development team for some period without scope definition but on the other hand he will be able to decide to stop cooperation at any time. Of course scope of the project will be defined during daily work as it is in Scrum process. Right now only customer has advantage. We should think also about development team. Together with option to stop cooperation at any time customer will need to promise that he will pay part of money he would pay if cooperation would continue (for example 20% value of rest of contract).
In such scenario both sides are winners. Customer will get software that is adjusted for his needs. He can also resign from further cooperation when he will find out that provided solution is good enough for him. He will also get bonus by decreasing cost of development (as in example – he will pay only 20% rest of development costs).
In case of solution provider we should mention about two benefits. First of all he will be able to use development team faster than he planned it before. So they will be able to start delivering new value for him. Moreover he will gain additional money – that customer will pay for earlier ending of cooperation.
I encourage you to try this approach. I think this solution is fair for both sides and you will be able to provide better software to customer.