Footnotes

Chapter 1

1. In this book we use the term “element” when we mean either a module or a component, and don’t want to distinguish.

Chapter 5

1. When the detection mechanism is implemented using a counter or timer that is periodically reset, this specialization of system monitor is referred to as a “watchdog.” During nominal operation, the process being monitored will periodically reset the watchdog counter/timer as part of its signal that it’s working correctly; this is sometimes referred to as “petting the watchdog.”

2. A protection group is a group of processing nodes where one or more nodes are “active,” with the remaining nodes in the protection group serving as redundant spares.

3. These tactics deal with runtime means to prevent faults from occurring. Of course, an excellent way to prevent faults—at least in the system you’re building, if not in systems that your system must interact with—is to produce high-quality code. This can be done by means of code inspections, pair programming, solid requirements reviews, and a host of other good engineering practices.

Chapter 8

1. A critical section is a section of code in a multi-threaded system in which at most one thread may be active at any time.

Chapter 16

1. This material was adapted from [Barbacci 03].

Chapter 18

1. The uses view is a module view. It shows the uses structure discussed in Chapter 1.

Chapter 20

1. This use of the term “view” is consistent with our definition in Chapter 18: “a representation of a set of system elements and relations among them.”

Chapter 21

1. This is a common facilitated brainstorming technique.

Chapter 23

1. In the presentation of the DAWG case study, we only show the reduced set of scenarios.

Chapter 24

1. Some writers speak of the importance of experience. We count experience as a form of knowledge.