Development speed vs accelleration

Some days ago, I had a discussion with some of my colleagues about what percentage of a project budget should be spent on "overhead" activities, such as planning, tracking, reporting, documenting, process improvement or configuration management. Some argued that it should be less than 10%, other said it could be up to 50% of the total effort spent.
The argument is that a development project is supposed to development a product, so the core activity should be on engineering activities. Sounds reasonable to me.

Then I read the article about process improvement at Toyota, where it is claimed that the core activity of the organization has become "improving the process of making products" and the production/development of the product is a side-effect of it. The idea is simple: you will win from any competitors if you improve faster and/or longer than they do. Or put differently:

• Speed wins over distance.
• Acceleration wins over speed.
• Accelerated acceleration wins over acceleration.

Now I revisited the original question: "What percentage of the budget should we spend on 'overhead'?" The answer became very simple: increase the percentage if it increases your business value. When it reaches 50%, or 60% or 90%, it does not matter as long as it is good for business. As with Toyota, this may imply that the core competence of the company will change (from making cars to improving the way cars are made). If for example only10% of the company are technical experts contributing to making the product, the company becomes a non-technical company.

When extrapolating this to the career challenges, it does not really matter whether I am good at what I do or not. Good technical skills, good social skills are nothing to be jealous about. Good learning skills, especially the learning skills to improve your learning skills, are ultimately what's going to make the difference.