Patterns in software engineering – An Introduction

What is a pattern? (in software engineering world)

A predefined solution for a problem for the given context.

Key words in the above definition is problem, solution and the context.

What are the different categories of the patterns ? (in software engineering)

  • Analysis patterns
  • Design patterns
  • Architectural patterns
  • Technology patterns
  • Integration patterns

Why do we use the patterns?

Objective of patterns is to enhance

  • Reusabililty
  • Repeatability

in return will fetch

  • Cost efficiency
  • Agility (time to market)

Where the pattern concepts started in general ?

The pattern concept has been in use for thousands of years. In the building architecture and design, we have been using the patterns quite extensively. Ancient buildings like pyramids, roman collegium and lot more used the patterns in the implementation. For instance, the pillars used in ancient temples built in Thailand, India and etc are patterns. They did not design the pillars every time. The pillars are to hold the load of the building. We can notice the reusability and repeatability of the pillars in multiple places in those ancient building architecture which in returned improved the ancients to be effective and quick.

What are the types of patterns in each category?

There are conceptual, logical and physical patterns in each category. Conceptual patterns are very high level solution for the given problem at the given context. Physical patterns spells out the implementation solution for the given problem at the given context. Logical patterns are between physical and conceptual.

Software system architecture definition model

Consistency and repeatability in the architecture definition process is a must have requirement in an organization. It is like parents teaching some moral lessons to the kids. Kids will watch the parents if parents do practice what they teach them. If parents does not practice what they teach the kids, the kids are not going to buy-in to the parent’s teaching. Same situation with the architects. Architects emphasis and promote consistency, repeatability, efficiency and etc to the project team and if they do not practice those imperatives in their process and work product, it is going to be a hard sell for them.

Picture speaks more than thousand words. The above diagram illustrates a model, software system architects would follow to define the architecture blue print. The architect’s tool box are the knowledge gained through the internal process, individual experience, continuous improvement. The reference model and pattern catalog provides a framework for repeatability in the architecture definition process and in return implements those imperatives in the end product of the process. ie. software system architecture blueprint.