From the Financial Times:
“This is the fifth minister in this role in less than three years. The constant changing of faces and portfolios has been unhelpful to building a long-term dialogue, so it is important that we now see a period of stability,” said Lucy Findlay, head of enterprise at the CBI.
Exactly the same question should be asked about how a minister is supposed to form a working relationship with their Civil Servants and other stakeholders, understand their jobs and impose their authority on a government department in such a short stretch of time. Five ministers in three years is pretty bad but the problem of short-term ministers is endemic across the Government. The Better Government position paper (PDF) describes how, since the war, the average time that a minister has stayed in a post has been under two years.