1. A computer implemented method for determining a risk/reward model for a service to be provided by a service provider to a serviced entity comprising: receiving a service provider value function for the service from the service provider, the service provider value function being dependent on at least one service provider value parameter, the service concerns at least part of the serviced entity's information technology environment; receiving a serviced entity value function for the service from the serviced entity, the serviced entity value function being dependent on at least one serviced entity value parameter; receiving weighting values for both the serviced entity value function and the service provider value function; receiving a serviced entity base case from the serviced entity, the serviced entity base case representative of the at least one serviced entity value parameter without provision of the service by the service provider; receiving a set of projects and their interdependencies from the serviced entity, the set of projects and their interdependencies being eligible to the service provider to perform, each project having a given impact on the at least one serviced entity value parameter or the at least one service provider value parameter; determining the risk/reward model through performing and optimizing a selection of the set of projects, resulting in a selection set, the performing and optimizing based on optimization criteria derived from the serviced entity value function, the weighting value for the serviced entity value function, the service provider value function, the weighting value for the service provider value function, the serviced entity base case, a risk share and/or a reward share between the service provider and the serviced entity, an active service time period of the service to be provided by the service provider, and a transition time period beginning right after the active service time period; and outputting a risk/reward line for the service to be provided relative to the at least one serviced entity value parameter, and the risk/reward line represents whether a reward or penalty is accredited to the service provider depending on achieved results relative to the risk/reward line, the risk reward line being derived from the risk reward model, wherein the steps of receiving, determining and outputting are performed by a computer.