diffuse responsibilities

I think you could "diffuse tensions", but could you diffuse responsibilities? I want to express the idea that responsibilities were discharged from a higher level to a lower level of management, what kind of verbs could I use with responsibilities? Do you think that I should use the singular form of "improvements"? Could you specify the reasons? Any other problem with this sentence?

Japanese corporate innovation was not immediately evident from the outside, because much of the manufaturing improvements, such as quality circles and just-in-time manufacturing, took place at the assembly-line level, as responsibilities were diffused from the executive office to the plant floor.

Delegate responsibilities, diffuse doesn't sound right with responsibilities.

What about "discharge"? Could you give me other options to rich my expressions? Do you think that I should use the singular form of "improvements"? Could you specify the reasons? Any other problem with this sentence?

I don't think you should use the singular of improvements because there was more than one improvement. You could say responsibilities were discharged, but delegated is better - it's what we usually say about responsibilities if they are passed from one person to another - they are delegated.

Thanks Sally! Could you give me other options to rich my expressions?Any other problem with this sentence?

Could I say "pass responsibilities"?

Responsibilities are usually delegated.