In the past I've explained this as a comparison of Costs and Outcomes. The total cost of the plan, and the outcomes (mostly as benefits). In the GP's example

In the past I've explained this as a comparison of Costs and Outcomes. The total cost of the plan, and the outcomes (mostly as benefits). In the GP's example it could have been, for example, the cost in time for the existing to develop the iOS application, the opportunity cost that's being given up by causing schedule slippages, and the discretionary effort of staff based on doing unfavorable work for the benefits of reducing management complexity, upskilling existing staff, and gaining a wider variety of experience within the team. Alternatives such as using a supplier to build the iOS have their own costs and outcomes. For example, cost in terms of capital dollars, a technical person still needs to invest time in finding the correct supplier, a technical person still needs to invest time into creating the specification to build upon (even if you find a supplier which can do agile and incremental delivery/iteration), and management overhead for managing the team and/or relationship with the supplier. Further, since the product is something that needs to be maintained (presumably), a maintenance plan of some sort will need to be put into place, and for the benefit of getting it done more quickly, a better product by developers interested and competent in the domain the total cost will likely be lower, and other projects will slip less. There's also the advantage that if management has to put in capital dollars then they are more likely to take the project seriously and fund its maintenance and reward those involved, especially if that's accounted for up front.