Please answer a question about the following article about The Blitz:

The relieved British began to assess the impact of the Blitz in August 1941, and the RAF Air Staff used the German experience to improve Bomber Command's offensives. They concluded bombers should strike a single target each night and use more incendiaries because they had a greater impact on production than high explosives. They also noted regional production was severely disrupted when city centres were devastated through the loss of administrative offices, utilities and transport. They believed the Luftwaffe had failed in precision attack, and concluded the German example of area attack using incendiaries was the way forward for operations over Germany.

What caused the most production disruption?
when city centres were devastated through the loss of administrative offices, utilities and transport.