Design fundamentals: Design characteristics

Before we can begin exploring the details of service-oriented computing, we first need to establish some basic design terminology. The books in this series use a common vocabulary comprised of the following design-related terms:

• Design Characteristic
• Design Principle
• Design Paradigm
• Design Pattern
• Design Pattern Language
• Design Standard
• Best Practice

Depending on your sources, you will find differing definitions for these terms. More often than not, though, you will notice that they all are somewhat intertwined. The following sections explain each term and conclude with a section that illustrates how they form a common, fundamental design framework.

Design Characteristic

A characteristic of something is simply an attribute or quality. An automated business solution will have numerous unique characteristics that were established during its initial design (Figure 3.1). Hence, the type of design characteristic we are interested in is a specific attribute or quality of a body of solution logic that we document in a design specification and plan to realize in development.

Figure 3.1

In this simple example, three distinct application designs (A, B, C) are established, each with its own list of design characteristics. We will continue to reference these applications in the upcoming sections. (Note that the small squares represent units of solution logic, solid arrows represent reuse or shared access, and dashed arrows represent state data transfer.)

Service-orientation emphasizes the creation of very specific design characteristics, while also de-emphasizing others. It is important to note that almost every design characteristic we explore is attainable to a certain measure. This means that it is generally not about whether solution logic does or does not have a certain characteristic; it is almost always about the extent to which a characteristic can or should be realized.

Although each system can have its own unique characteristics, we are primarily interested in establishing common design characteristics. Increased commonality ensures an increased degree of consistency, making different kinds of solution logic more alike. When things are more alike they become more predictable. In the world of distributed, shareable logic, predictability is a good thing. Predictable design characteristics lead to predictable behavior. This, in turn, leads to increased reliability and the opportunity to leverage solution logic in many different ways.

Much of this book is dedicated to providing a means of establishing a specific collection of design characteristics that spread consistency, predictability, and reliability on many levels and for different purposes.

Use the following table of contents to navigate to chapter excerpts

SOA: Principles of Service Design
  Home: Service-oriented computing and SOA: Introduction
  1: Design fundamentals: Design characteristics
  2: Design fundamentals: Design principles and design paradigm
  3:Design fundamentals: Design pattern and design pattern language
  4:Design fundamentals: Design standard
  5:Design fundamentals: Best practices
  6:Introduction to service-oriented computing
  7:Service oriented architecture
  8:Service compositions
  9:Understanding service oriented computing elements
  10:Entity services
  11:Web services and service oriented computing
  12:Service inventory blueprints
  13:Service-oriented analysis and service modeling
  14:Service-oriented design
  15:Goals and benefits of service-oriented computing
  16:Increased intrinsic interoperability
  17:Increased federation
  18:Increased vendor diversification options
  19:Increased business and technology domain alignment
  20:Increased ROI
  21:Increased organizational agility
  22: Reduced IT burden