Trade Off Triangle
Traditional Trade Off Triangle
Source: MSF 3.0
| TOT | Fixed | Chosen | Adjustable |
| Resources | X | | |
| Schedule | | X | |
| Features | | | X |
In this model the example shows that the resources are known and fixed up front and schedule agreed upon with the client. The feature set is adjustable by the software company.
Optional Scope Contract
Source: Kent Beck
The rule here is to allow the client to have control of any two rows and the software company controls the third.
| OSC | SP | Client |
| Price | X | - |
| Schedule | - | X |
| Features | - | X |
In this example the client can adjust the time and scope but the software provider controls the price.