Mr Jack said staff were aware some positions would be coming under the review microscope.
"They have been fully engaged in this process."
Mr Jack said the restructuring of the museum was the same as any business which had gone through a start-up process and that the report had been taken aboard.
"We are tweaking how it operates - it is about getting the right structure."
He said he was tiring of the barrage of criticism being levelled at what he described as a smart and strong new building which had been delivered on budget and which had already picked up a major professional award.
The first changes had already been made in the reduced admission costs.
The full process was expected to take about six months and he and the council had confidence in director Douglas Lloyd Jenkins and the curator team.
"This (report) has given him direction," Mr Jack said. Mr Lloyd Jenkins said he welcomed the decision to cut the entry cost and was enthusiastic about plans to place more focus on marketing. He also said there was a determination to "deal" with too many open walls in the wake of claims within the report that the museum appeared minimalist.