Decomposition

Decomposition is one of the four cornerstones of Computational thinking. It involves breaking down a complex problem or system into smaller parts that are more manageable and easier to understand. The smaller parts can then be examined and solved, or designed individually, as they are simpler to work with.

Breaking bigger problems down into smaller ones that are easier to solve is called the structured approach in computer science. Instead of writing lots of lines of code in one go, we break the problem down and write subroutines or functions to solve each part

Decomposition in practice

We do many tasks on a daily basis without even thinking about - or decomposing - them, such as brushing our teeth.

Example 1: Brushing our teeth

To decompose the problem of how to brush our teeth, what would we need to consider?

Example 2: Solving a crime

It is only normally when we are asked to do a new or more complex task that we start to think about it in detail - to decompose the task.

Imagine that a crime has been committed. Solving a crime can be a very complex problem as there are many things to consider.

How would we decompose the task of solving a crime?

To summarise - Decompostion can be though as a process involving the following steps:

1. Identifying and describing problems and processes
2. Breaking down problems and processes into distinct steps
3. Describing problems and processes as a set of structured steps
4. Communicating the key features of problems and processes to others