At the age of 54, he is opting out of senior administration at the end of April as his fixed five-year contract expires. "It is my decision to go, not the council's," Mr McMurdo said this week.
Almost three years ago he hinted he was in line for an early exit. In a TES Scotland profile he said that when his contract ended his main ambition was to leave behind an effective department that continued to offer better opportunities for young people.
Mr McMurdo appears to have done just that after being highly praised by inspectors last June for his "drive and commitment" in running education in the second most economically deprived Scottish authority where many pupils face tough lives.
"I come from a very similar background to theirs and I know the kind of problems they have to face. So if ever I start feeling that life is tough, I just remind myself how privileged I really am," he said in 2001.
The authority, which he has headed since local government reorganisation in 1996, recently proclaimed that it would be an illiteracy-free zone within four years after stepping up intensive work with poor readers in primary.
One in four P7 pupils is said to enter secondary unable to read well enough to cope.
The initiative helped inspectors to commend the authority for its work on raising attainment in primaries where the rate of improvement is faster than comparable councils and the national average. It emerged safely in the upper echelons of local authority inspections, with three very goods and seven goods from HMI.
Mr McMurdo, a native of Cumnock in East Ayrshire, where he still lives, will shortly give up the daily commute to Dumbarton, a factor that no doubt played strongly in his decision.
His post is advertised today (Friday) in our Scotland Plus section.