Manufacturing of parts

The goal of my business idea is to create a company that will include all types of production machines, as my branch in which I plan to progress. The company will produce all kinds of parts, whether in serial production or only by order for a certain part.
In the initial stage I would buy machines that are necessary for the production of not so complex parts, machines such as universal lathe, milling machine, grinder, drill. Those machines on our market do not require too much starting capital and are great to start with, because parts can be produced without bigger difficulties and machines can be found for an affordable price. With such a set of machines, the parts will be manufactured by order, for example when a local company or company that works with machines for any production, needs a part that can be made on these machines, they would contact my company, set the conditions and requirements for the part, then I will make the part and I will charge accordingly.
In the second stage of my company's development, I plan to increase the set of machines, by buying machines such as 3D printer and injection molding machine. Serial parts can already be produced at this stage, but they would be made of plastic, and the possibility of making metal parts in serial production would not yet be available. The supply market will certainly be expanded to include larger companies and factories that need parts. With the increase in the number of machines, a qualified staff is needed, with which I will be able to work. Depending on the demand for my service I will hire people who know how to work on these machines and would have at least 3 years of experience.
In the final stage, I would already have modern numerically controlled machines, with experienced operators, that would allow me to produce a large selection of parts, regardless of the material required. The employed staff will certainly need to be qualified with a university degree and knowledge of a good part of mechanical engineering. The target groups would be large factories and corporations, which need parts that are expendable and will quickly wear out and need to be changed frequently, as well as companies outside the country that manufacture a product and I need to produce a component of the product. For the production of a component that will go into serial production, automated machines are needed and they will be intended only for the production of that component. Operating these machines requires supervising operators and they do not have to be highly qualified.
Fulfilling my business idea is possible with a lot of effort and work. It does not require a lot of capital to start and depending on the demand, the set of machines would increase. As the human population grows, so will the demand for food, clothing, telephones, cars etc. In order to have such items, they need to be produced, so I think that production will never die and is a business in which I would like to invest.