Software Architecture in Practice Quotes

“If change is the only constant in the universe, then software change is not only constant but ubiquitous.”
― Len Bass, Software Architecture in Practice

“Quality is not an act, it is a habit. —Aristotle”
― Len Bass, Software Architecture in Practice

“An architecture that is not documented, and not communicated, may still be a good architecture, but the risks surrounding it are enormous. —RK”
― Len Bass, Software Architecture in Practice

“The software architecture of a system is the set of structures needed to reason about the system, which comprise software elements, relations among them, and properties of both.”
― Len Bass, Software Architecture in Practice

“By its very nature every architecture is a statement about what we expect to remain constant and what we admit may vary.”
― Len Bass, Software Architecture in Practice

“Coming together is a beginning. Keeping together is progress. Working together is success. —Henry Ford”
― Len Bass, Software Architecture in Practice

“Performance Tactics on the Road Tactics are generic design principles. To exercise this point, think about the design of the systems of roads and highways where you live. Traffic engineers employ a bunch of design “tricks” to optimize the performance of these complex systems, where performance has a number of measures, such as throughput (how many cars per hour get from the suburbs to the football stadium), average-case latency (how long it takes, on average, to get from your house to downtown), and worst-case latency (how long does it take an emergency vehicle to get you to the hospital). What are these tricks? None other than our good old buddies, tactics. Let’s consider some examples: • Manage event rate. Lights on highway entrance ramps let cars onto the highway only at set intervals, and cars must wait (queue) on the ramp for their turn. • Prioritize events. Ambulances and police, with their lights and sirens going, have higher priority than ordinary citizens; some highways have high-occupancy vehicle (HOV) lanes, giving priority to vehicles with two or more occupants. • Maintain multiple copies. Add traffic lanes to existing roads, or build parallel routes. In addition, there are some tricks that users of the system can employ: • Increase resources. Buy a Ferrari, for example. All other things being equal, the fastest car with a competent driver on an open road will get you to your destination more quickly. • Increase efficiency. Find a new route that is quicker and/or shorter than your current route. • Reduce computational overhead. You can drive closer to the car in front of you, or you can load more people into the same vehicle (that is, carpooling). What is the point of this discussion? To paraphrase Gertrude Stein: performance is performance is performance. Engineers have been analyzing and optimizing systems for centuries, trying to improve their performance, and they have been employing the same design strategies to do so. So you should feel some comfort in knowing that when you try to improve the performance of your computer-based system, you are applying tactics that have been thoroughly “road tested.” —RK”
― Len Bass, Software Architecture in Practice

“12.2 The Basis for the CBAM”
― Len Bass, Software Architecture in Practice