Mintzberg divides organisations into five parts.
The strategic apex is equivalent to top management or the Board of Directors.
The middle line is the middle managers, sometimes called the scalar chain. This is the hierarchy as it passes down through the organisation.
The operating core are the people near the bottom who for the most part do the day-to-day work.
Support staff would include the accounting staff and IT staff.
The technostructure. This is perhaps the hardest to understand and is the part of the organisation responsible for devising and enforcing standards and procedures. It is the technostructure that would write the quality control manual, the employee handbook, the health and safety manual, the finance manual.
As drawn initially:
the diagrams show what Mintzberg would have called the machine bureaucracy which is basically a large mass manufacturing organisation.
The size and importance of the five parts of the organisation change as we change the organisation. In an entrepreneurial organisation there will be a strategic apex and the operating core. You may remember that entrepreneurial organisation was a basically a boss and the workers with little middle line and the organisation was so small that there was not much support staff and no need for technostructure.
One of the most interesting adaptations of the basic structure is what Mintzberg called professional organisation.
He was thinking of something like a large firm of accountants and lawyers. In these organisations, the middle line is much shorter, representing that there is really quite a close relationship between the partners at the top of the organisation and the people doing the audit or legal work at the bottom. These people need to communicate and cooperate very closely. There are of course middle managers but the middle line is relatively short.
Support staff is still quite large. But what is surprising is that the technostructure is very small. This is perhaps surprising because auditors and lawyers have large files of standardised procedures, for example, audit programs to fill in, and you might think that audits and legal work were highly regulated and standardised. But if you think about it, every client an auditor goes to, or every client coming to see a lawyer, will have slightly different problems. We are not in the mass production manufacturing industry anymore. We are dealing with tailoring solutions to clients. So the technostructure, such as it is, represented by standard forms is somewhat superficial. Each client and each service has to be individually devised and delivered, so the power of the technostructure is relatively small.