Given the following state model of sales order software: PLACED -> IN PRODUCTION IN PRODUCTION -> CANCELLED IN PRODUCTION -> SHIPPED SHIPPED -> INVOICED INVOICED -> CANCELLED CANCELLED -> PLACED Which of the following sequences of tran-sitions provides the highest level of tran-sition coverage for the model (assuming you can start in any state)?

The goal is to achieve the highest transition coverage by exercising the maximum number of unique, valid transitions. The model has 6 unique transitions. The sequence in option B (IN PRODUCTION -> SHIPPED -> INVOICED -> CANCELLED -> PLACED -> IN PRODUCTION) covers 5 out of 6 unique transitions: (IN PRODUCTION -> SHIPPED), (SHIPPED -> INVOICED), (INVOICED -> CANCELLED), (CANCELLED -> PLACED), and (PLACED -> IN PRODUCTION). This is the highest coverage among the valid options.

A. This sequence covers only 3 unique transitions: (IN PRODUCTION -> CANCELLED), (CANCELLED -> PLACED), and (PLACED -> IN PRODUCTION).
C. This sequence contains an invalid transition. There is no direct transition from the SHIPPED state to the CANCELLED state in the given model.
D. This sequence contains an invalid transition. There is no direct transition from the PLACED state to the CANCELLED state in the given model.

ISTQB. (2023). Certified Tester Foundation Level Syllabus v4.0. Section 4.2.3, State Transition Testing, p. 39. "Test cases can be designed to cover a typical sequence of states, to cover every state, to exercise every transition, to exercise a specific sequence of transitions, or to test invalid transitions."

ISTQB. (2023). Glossary of Testing Terms v4.0. Definition of "transition coverage", p. 60.