The Mythical Man-Month Ch 16 - 17

Summary

Chapter 16 – No Silver Bullet – Essence and Accident in Software Engineering – In this chapter the author divides the difficulties in software development between essence and accidents. Essence describe the difficulties inherent in the nature of software; while accidents describe those difficulties that today attend its production but that are not inherent. He explains that in the next decade there will be no major technological or managerial development that will improve our productivity by one order of magnitude. The chapter describes how little has been done over the years to improve how we carry on the essential tasks so even with all the technological advances our productive has not yet improved by an order of magnitude because they have only addressed the accidental part of the equation.

Chapter 17 – “No Silver Bullet” Refired – the chapter divides the essence into four subcategories: complexity, conformity, changeability, and invisibility. Complexity refers to how no two parts of software entities are alike and how they have a huge number of states. Moreover, as the size of the system increases, its parts increase exponentially, and you can’t abstract away the complexity. Conformity refers to the arbitrary sets of rules and changes software has to go through. Changeability refers to how software is constantly asked to change. Finally, invisibility refers to how software is invisible and unvisualizable in contrast to other more tangible things and this lack of visualization deprives the engineer from using the brain’s powerful visual skills.  In this chapter the author reflects on a paper he wrote ten years before and clarifies certain misunderstandings. At the end he quotes what someone wrote about his paper that summarizes what he wants to say: “Software development is a conceptually tough business. Magic solutions are not just around the corner. It is the time for the practitioner to examine evolutionary improvements rather than to wait-or hope- for revolutionary ones.

Discussion

I agree with most of the things he says in Chapter 16. However, I believe we have improved a lot in meeting customer needs and this in turn has helped improve productivity. Probably not a lot compared to how much more productive these methods should have become. In any case, he is right about how tough of a business is software development and how we should be examining evolutionary improvements.