ASTQB Exam CTAL Topic 2 Question 53 Discussion

A major bank has recently outsourced all of its software development in an effort to reduce its fixed costs. The new supplier will be responsible for all new developments as well as enhancements to existing ones. The bank has retained its own management team for its projects. There will be an in-house project manager, development manager and test manager for each project. Some staff may work on more than one project, depending on the overall size. An enhancement is being made to allow existing customers to authorise their own loans online, from 1k to 10k by answering a series of questions. You are a test manager with the bank and you have written a test strategy for the outsourced team to follow. Unit testing has begun but informal conversations with the developers have revealed that they have not received a signed-off specification from the bank for the enhancement. They do know how loans work though and have created code from conversations with bank staff alongside their own knowledge. How could a strategy have helped to avoid this situation?