Grady Booch (Collected Quotes)

"An abstraction denotes the essential characteristics of an object that distinguish it from all other kinds of object and thus provide crisply defined conceptual boundaries, relative to the perspective of the viewer." (Grady Booch, "Object-Oriented Design with Applications", 1991)

"[...] encapsulation - also known as information hiding - prevents clients from seeing its inside view, were the behavior of the abstraction is implemented." (Grady Booch, "Object-Oriented Design With Applications", 1991)

"Every software system needs to have a simple yet powerful organizational philosophy (think of it as the software equivalent of a sound bite that describes the system's architecture). [A] step in [the] development process is to articulate this architectural framework, so that we might have a stable foundation upon which to evolve the system's function points." (Grady Booch, "Object-Oriented Design: with Applications", 1991)

"In object-oriented analysis, we seek to model the world by identifying the classes and objects that form the vocabulary of the problem domain, and in object-oriented design, we invent the abstractions and mechanisms that provide the behavior that this model requires." (Grady Booch, "Object-Oriented Design: With Applications", 1991) 

"Object-oriented analysis is a method of analysis that examines requirements from the perspective of the classes and objects found in the vocabulary of the problem domain."(Grady Booch, "Object-oriented design: With Applications", 1991)

"Object-oriented programming is a method of implementation in which programs are organized as cooperative collections of objects, each of which represents an instance of some class, and whose classes are all members of a hierarchy of classes united via inheritance relationships." (Grady Booch, "Object-oriented design: With Applications", 1991)

"Structured design does not scale up well for extremely complex systems, and this method is largely inappropriate for use with object-based and object-oriented programming languages." (Grady Booch, "Object-oriented design: With Applications", 1991) 

"The object-oriented paradigm is useful when building software systems where there is a hierarchy defined as a ranking or ordering of abstractions. (Grady Booch, "Object-Oriented Design: With Applications", 1991)

"Whereas object-oriented analysis typically focuses upon one specific problem at a time, domain analysis seeks to identify the classes and objects that are common to all applications within a given domain, such as missile avionics systems, compilers, or accounting software." (Grady Booch, "Object-oriented design: With Applications", 1991)

"As a noun, design is the named (although sometimes unnamable) structure or behavior of a system whose presence resolves or contributes to the resolution of a force or forces on that system. A design thus represents one point in a potential decision space. A design may be singular (representing a leaf decision) or it may be collective (representing a set of other decisions). As a verb, design is the activity of making such decisions. Given a large set of forces, a relatively malleable set of materials, and a large landscape upon which to play, the resulting decision space may be large and complex. As such, there is a science associated with design (empirical analysis can point us to optimal regions or exact points in this design space) as well as an art (within the degrees of freedom that range beyond an empirical decision; there are opportunities for elegance, beauty, simplicity, novelty, and cleverness). All architecture is design but not all design is architecture. Architecture represents the significant design decisions that shape a system, where significant is measured by cost of change." (Grady Booch, "On design", 2006)