Qualification:
Cambridge Advanced National in Computing (AAQ)
Unit:
F160: Fundamentals of Application Development
Certificate:
Computing: Application Development (H029 / H129)
4.3 - Decomposition Methods
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Abstraction
Pattern Recognition
Modularisation
Parsing of Requirements
Decomposition methods break complex problems or systems into smaller, more manageable parts. This makes development easier to plan, understand and implement.
Decomposition also helps reduce errors and improve efficiency, as individual tasks can be more easily tested and debugged.
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For each of the four decomposition methods (abstraction, pattern recognition, top-down and bottom-up modularisation and parsing requirements) you need to know when each method is suitable to use, its advantages and disadvantages, how client requirements affect their selection and how they can be used to visualise application designs.​
Decomposition Methods
Abstraction
Abstraction is the process of simplifying a problem by ignoring irrelevant data and focusing only on the most important details.
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It is used in the early stages of design or planning, when managing complexity in large systems and when creating reusable components.
Pattern Recognition
Pattern recognition is used to identify similarities or trends in problems or client requirements. This allows for the reuse of existing components and aids in finding solutions for common issues.
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It is used during the planning or analysis phases and when dealing with similar tasks, inputs, outputs or processes.
Modularisation
Modularisation refers to the individual components that make up a larger project.
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In top-down modularisation, a larger system is broken down from a general overview into its most specific parts.
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The purpose of bottom-up modularisation is to build the system starting with the smaller, detailed components and combining them into larger subsystems.
Parsing of Requirements
To parse requirements means to systematically break down and analyse client requirements into actionable tasks or functions.
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It is used at the start of a project to ensure shared understanding between development teams and clients.
Questo's Questions
4.3 - Decomposition Methods:
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1. Explain the differences between top-down and bottom-up modularisation. [4]
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2. Explain when abstraction would be an appropriate decomposition method to use. ​[3]
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3. What are the advantages and disadvantages of parsing requirements? ​[4]​
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4. Give one way each decomposition method can be used in software application development. [4]​
Alan Turing and his team used pattern recognition to analyse recurring sequences in encrypted German messages, helping to break the Enigma code, which was a major factor in the Allies’ victory in World War II.
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