Your Academic Training
The foundation of your technical knowledge base is your academic training. Not only did it teach you formal mathematics, science, and some particulars of your specialty, but it should have given you an intuitive insight and understanding of the behavior of those parts of nature with which you deal. Really understanding calculus as a description of nature is a kind of litmus test of whether you actually learned engineering or just learned cookbook procedures for solving standardized problems.
Your academic training may have stopped at the bachelor's-degree level or may have extended to the master's or doctor's level. It may also include any number of single courses given by university extensions, professional societies, and commercial "seminar" companies.
Technicians and engineering
In general, it is a wishful delusion for technicians (including drafters and non-engineer designers) to believe that they can become real engineers by the accumulation of practical experience. The mathematics and science components of formal education are missing from such experience. This is sometimes hard for non-engineers to believe, but it takes a lot of education to know what you don't know.
Continuing Professional Study
After mathematics and science is the art in the field in which you work. (Art is patent language for technology. Using the word "art" saves syllables.) This includes old art, now abandoned, but containing ideas which may not be used in current practice. Knowledge of the current art as practiced in your own organization, in competing organizations, and in research laboratories prevents you from wasting effort in reinventing wheels and gives you a basis for advancing your art.
The principal way you get this knowledge is by study of books and journals in school and for the rest of your working life. Journals include "blue books," which are the scholarly publications of technical societies, and the more easily understood trade journals, many of which are giveaways. The most valuable portion of the trade journals is their advertisements. Many of these are very carefully written and illustrated by communication experts because it is of great importance to the advertisers that you understand their products easily and well. The technical merit of the articles often leaves much to be desired, but they are excellent sources of superficial information about fields other than your own. There are scientific and engineering journals of general interest such as Scientific American, American Scientist, and some engineering school publications which are rich sources of information and new ideas. There are similar journals for those without scientific or engineering training which are easy to read and introduce new ideas, e.g., Omni and Popular Mechanics.
Technical society lectures present material before it is published, and you can learn much from conversation with others who attend them. The quality of these lectures varies widely. The lectures are usually printed later on.
New textbooks may be published in your field, some with new in-formation.
Advanced Degree
Should you really study for an advanced degree? Maybe. It costs a great deal of time and a significant sum of money. If you have a family, you must neglect it to an emotionally costly degree. If you have chosen the low-tech branch, the education may be irrelevant to your work and not very helpful to your job progress. A smaller amount of time spent in reading trade journals and catalogs and attending trade shows may pay off much more for you.
On the other hand, if you can afford the time and money as an in-vestment in your future, if you are on or want to be on the high-tech branch, if you really enjoy mathematical engineering, if you want to do advanced research, particularly in a university, or if you want to teach, the advanced degree is essential. (For university work and teaching, "advanced" means Ph.D., the professors' "union card.")
General Knowledge
Knowledge of your own field is not enough. If you would invent in your field, you will find it of enormous value to have knowledge of all other fields and the broadest possible knowledge of nontechnical information and ideas. A classic story in chemistry is of the scientist who conceived the benzene ring. In struggling with his problem he had a fantasy of a snake consisting of a chain of elements; as the snake moved around in his mind, it put its tail in its mouth, and he suddenly realized that this ring structure, the benzene ring, explained the phenomena he was studying, although herpetology was not his business.
No one knows all the raw materials which now exist, and there is a continual generation of new materials. Many new designs are made possible by the availability of new materials. Therefore it behooves you to watch continually for both old and new materials you might use.
Commercial Components and Vendors
Most product designs include at least some purchased commercial components. It therefore will benefit you to know all about components, not only in your own field but also those developed for other fields, which you might use. It is useful to build your own catalog file of components and materials which you think you might use someday.
Become acquainted with the manufacturer's directories in your field. They are the best guide to materials, components, and services as well as to products competitive with your own.
Contract Manufacturers
Sooner or later you will conceive a new product or component which your organization is not qualified to build. There is a large world of specialized contract manufacturers who have equipment or technology which it is not economical for your organization to acquire but who are eager to make unusual components for you. They are represented by sales engineers who are eager to teach you their technologies in the hope that you will eventually buy their services. Free trade literature and sometimes free trial fabrication are offered by them.
Manufacturing Technologies
Whatever you design must be manufactured if your design is to have value. It therefore behooves you to learn the manufacturing technologies useful for making the products you design or might design. All designers usually have in the back of their minds a technology usable in producing their designs; no one wants to design something that can't be made. If designers are uneducated in manufacturing technology, they will either limit their designs to things they do know how to make or will design products which are needlessly expensive to make. Furthermore, knowledge of manufacturing processes will sometimes help you to conceive new components and assemblies to be manufactured. Your knowledge of manufacturing technology should include an understanding of the relationship between quantity and cost for each technique and knowledge of the many techniques for making models and small preproduction runs. An excellent source of knowledge of unusual technologies is the catalogs of contract manufacturers. Some catalogs are specialized engineering handbooks.
Trade Shows
Trade shows are rich sources of technical knowledge, particularly of components and materials. You see the real thing, and you can talk to exhibitors who are expert in their products and their application.
