We have three features, the Scara which is the hardware arm that move the marker locally. The end-effector is connected to the end of the Scara and has the task to lift the marker from the board and to release it. And the last feature is the carriage which has the task to move the Scara with the end-effector. Sub feature of the carriage will be some kind of base structure where the Scara will be mounted on. In this base we will also store the different tools.
We constructed the following table to select a feature. From this we can derive that the end-effector is prefered over the carriage.
| Feature | Dependency | Test Coverage | Risk | Time | Risk/Time factor |
|---|---|---|---|---|---|
| Scara | End-effector | 3 | medium | medium | 1 |
| End-effector | - | 2 | high | medium | 2 |
| Carriage | - | 2 | low | medium | 0.5 |