To Engineer is Human
Glancing through the book "To Engineer is Human" by Henry Petroski (one of my favourites -- I had earlier quoted a passage from the book which quoted from Herbert Hoover about the engineering profession's hazards, I was once again reminded about the numerous parallels between what the book describes (it emphasizes structural/civil engineering, drawing examples from bridges, buses, materials, etc) and software engineering. For instance, in chapter 4 "Engineering as hypothesis", he describes the definition of structural engineering, which The Structural Engineer, the official journal of the British Institution of Structural Engineers, carries on its contents page: Structural engineering is the science and art of designing and making, with economy and elegance, buildings, bridges, frameworks, and other similar structures so that they can safely resist the forces to which they may be subjected Each time I see that passage, I am struck by how close that comes to defining software engineering - a few slight changes and we could have Software engineering is the science and art of designing and writing, with economy and elegance, applications, libraries, systems, and other similar programs so that they can safely resist the forces to which they may be subjected The book is strongly recommended reading. Petroski carefully analyzes the problems of failure, and the lessons to be learnt. Some specific details are obviously not relevant (but still interesting) eg. the discussion on metal fatigue, but the overall perspective is relevant to any profession involved in designing/building practical contrivances. Other quotes: Thus it is the essence of modern engineering not only to be able to check one's own work, but also to have one's work checked and to be able to check the work of others. In order for this to be done, the work must follow certain conventions, conform to certain standards, and be an understandable piece of technical communication. Success is foreseeing failure. Economic constraints are often imposed by the demands of the marketplace, but the requirement for elegance is ofte self-imposed by the best in the profession in much the same way as artists and scientists alike see elegance i the sparest canvases and the most compact theories -- or in the axiom of minimalist aesthetics and design, "less is more". "Is it becoming easy to take on design work outside an engineer's area of expertise simply because a software package is available? How can civil engineers guarantee the accuracy of the computer program and that the engineer is qualified to use it properly?" - quote from the announcement for the Mead Prize competition for the best paper on the topic "Should the Computer be Registered" by the American Society of Civil Engineers. Bugs entered engineering calculations long before the computer, and wondering whether he had thought of every possible failure mode has kept many an engineer awake (at night). (He has a fascinating anecdote about his search to check the antecedents of the famous quote "Those who cannot remember the past are condemned to repeat it" from George Santayana's "The Life of Reason". He also quotes Santayana "We must welcome the future, remembering that it will soon be the past; and we must respect the past, knowing that it was once all that was humanly possible.) Engineering, like poetry, is an attempt to approach perfection. And engineers, like poets, are seldom completely satisfied with their creations. No one wants to learn by mistakes, but we cannot learn enough from successes to go beyond the state of the art.