Cambridge IGCSE0417

Analysis

Information Communication Technology 0417 Chapter Notes

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AnalysisDesignDevelopment and testingImplementationDocumentationEvaluation
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In this chapter

  1. 1The Purpose of Systems Analysis
  2. 2Information Gathering Methods
  3. 3Recording and Analysing Findings
  4. 4The System Specification

1. The Purpose of Systems Analysis

Systems analysis is the first crucial step in developing or improving a computer system. It's like a detective's investigation. A systems analyst studies an existing system to understand how it works, identify its problems (like bottlenecks, errors, or inefficiencies), and figure out what the users and the organisation need from a new system. The main goal is to gather enough information to produce a detailed 'System Specification' document, which acts as a blueprint for the designers and programmers who will build the new system.

Key term

Systems Analyst: A professional who specialises in analysing, designing, and implementing systems to suit the needs of an organisation and its users.

Examiner insight

Examiners look for a clear understanding that analysis is about 'what' the system should do, not 'how' it will do it, which is covered in the design stage.

Fun fact

Early systems analysts in the 1950s and 60s often had backgrounds in accounting or industrial engineering, as they were the first fields to be heavily computerised.

Worked example 14 marks

A school's current library system uses paper cards to track borrowed books. The headteacher wants to upgrade to a computerised system. Explain two problems the systems analyst might identify with the current system.

  1. 1
    1. Identify a problem related to efficiency: The current paper-based system is likely very slow. Finding a specific book's record or checking if a student has overdue books would involve manually searching through card files, which is time-consuming for the librarian.
  2. 2
    1. Identify a problem related to data integrity/security: Paper cards can be easily lost, damaged, or misplaced. This could lead to inaccurate records of who has borrowed which book, potentially causing disputes or loss of school property. There is no easy way to create a backup of the entire system.

Recap

  • Analysis is the first stage of the systems life cycle after the initial identification of a need.
  • The primary goal is to investigate and understand an existing system.
  • Analysis identifies problems and limitations of the current system.
  • It also determines the requirements for the new system from the users' perspective.
  • The final output of this stage is the System Specification document.
  • A Systems Analyst is the person responsible for carrying out the analysis.

Quick check

  1. State the main purpose of the analysis stage in the systems life cycle.1 mark
  2. What is the name of the document produced at the end of the analysis stage?1 mark

2. Information Gathering Methods

To understand the current system, a systems analyst must gather information. There are four main methods to do this. The analyst often uses a combination of these methods to get a complete and accurate picture.

  1. Observation: Watching users perform their daily tasks with the current system. This is good for understanding the actual workflow, not just the 'official' one.
  2. Interviews: Asking users and managers questions in a face-to-face setting. This allows for detailed, in-depth responses and follow-up questions.
  3. Questionnaires: Distributing a set of written questions to a large number of people. This is an efficient way to gather opinions and simple facts from a wide audience.
  4. Examining Documents: Collecting and studying existing paperwork, forms, reports, and manuals. This reveals the official inputs, processes, and outputs of the system.

Key term

Questionnaire: A set of pre-written questions, with a choice of answers, used to collect information from a large number of people.

Examiner insight

When asked to suggest a method, you must justify your choice in the context of the given scenario to earn full marks.

Common pitfall

Students often mix up the advantages and disadvantages of interviews and questionnaires. Remember: Interviews are for depth, questionnaires are for breadth.

Worked example 13 marks

A systems analyst is investigating the ticket booking system for a large cinema chain with 50 branches nationwide. Suggest the most appropriate method for gathering information from ticket-selling staff across all branches, and justify your choice.

  1. 1
    1. Suggested Method: Questionnaires.
  2. 2
    1. Justification 1: Questionnaires are ideal for gathering information from a large number of people who are geographically spread out, like the staff in 50 different cinemas.
  3. 3
    1. Justification 2: It would be too time-consuming and expensive to interview every staff member. Questionnaires can be distributed and collected electronically, making the process fast and efficient.

Worked example 22 marks

Describe one advantage and one disadvantage of using observation to analyse a system.

  1. 1
    1. Advantage: The analyst can gain a first-hand, reliable understanding of how the system actually works in practice, which may differ from how people say it works. It can reveal problems that users themselves are not aware of.
  2. 2
    1. Disadvantage: People may act differently when they know they are being observed (this is known as the Hawthorne effect), so the analyst might not see a true representation of normal working practices. It can also be very time-consuming.

Recap

  • Observation provides first-hand insights but can be time-consuming and people may act unnaturally.
  • Interviews allow for detailed answers and follow-up questions but are time-consuming to conduct with many people.
  • Questionnaires are excellent for gathering data from many people quickly but do not allow for detailed or follow-up questions.
  • Examining existing documents shows the formal inputs and outputs but may be outdated.
  • The best approach often involves a combination of these four methods.

Quick check

  1. Name two methods of gathering information during systems analysis.2 marks

3. Recording and Analysing Findings

After gathering information, the systems analyst must organise and analyse it to identify key elements. This involves identifying the system's inputs, processes, and outputs. The analyst looks for problems, such as data entry errors, delays (bottlenecks), or redundant tasks. They also identify the user and information requirements for the new system, which are often solutions to the problems found. This information is often visualised using diagrams. For example, a Data Flow Diagram (DFD) can be used to show how data moves through the system, where it is stored, and what processes act upon it. These diagrams help to clarify the analyst's understanding and communicate the findings to both users and designers.

Key term

Data Flow Diagram (DFD): A graphical representation of the 'flow' of data through an information system, modelling its process aspects.

Examiner insight

Examiners reward students who can clearly link an identified problem with a specific, sensible requirement for the new system.

Fun fact

The symbols used in Data Flow Diagrams were first popularised in the 1970s by computing pioneers like Tom DeMarco, and the basic principles are still relevant today for modelling systems.

Worked example 14 marks

During the analysis of a doctor's surgery appointment system, a systems analyst notices that receptionists write patient details on a paper slip, which is then passed to a second receptionist who types the details into the computer. Identify one problem with this process and suggest a requirement for the new system to solve it.

  1. 1
    1. Problem Identified: The process involves double-handling of data (writing then typing) and is inefficient. It introduces a delay and increases the chance of transcription errors when the second receptionist types the details from the slip.
  2. 2
    1. Suggested Requirement: The new system must allow the first receptionist who answers the phone to directly input patient appointment details into the computer system in real-time. This eliminates the need for paper slips and the second member of staff, improving efficiency and accuracy.

Recap

  • Analysis involves identifying the inputs, processes, and outputs of the current system.
  • A key activity is to find problems or bottlenecks in the existing system.
  • User requirements for the new system are defined based on these findings.
  • Diagrams, like Data Flow Diagrams, are used to model the system.
  • These models help to show how data moves, is processed, and is stored.
  • The goal is to build a clear picture of the current system and what the new one needs to achieve.

Quick check

  1. State three things an analyst looks to identify when investigating a current system.3 marks

4. The System Specification

The System Specification (also known as a requirements specification) is the most important document produced during the analysis stage. It is a formal, detailed document that describes exactly what the new system must do. It is the culmination of all the investigation and analysis work. This document acts as a contract between the client/users and the development team. It forms the basis for the design stage. Any disagreements later in the project can be settled by referring back to this document.

Key term

System Specification: A detailed document produced at the end of the analysis stage that outlines the requirements for a new system.

Examiner insight

Marks are often awarded for identifying different types of requirements, such as user requirements (what the user needs to do) and hardware/software requirements (the technical platform needed).

Common pitfall

Confusing the System Specification (from the Analysis stage) with the Design Specification (from the Design stage). The System Spec says 'what' is needed; the Design Spec says 'how' it will be built.

Worked example 16 marks

A new online shopping system is being developed. List and describe three items of information you would expect to find in the 'User Requirements' section of its System Specification.

  1. 1
    1. Functional Requirement: The system must allow customers to create a personal account and log in. This would involve specifying that users need to be able to register with an email and password.
  2. 2
    1. Functional Requirement: The system must have a search facility. This would specify that customers should be able to search for products by name, category, or brand.
  3. 3
    1. Performance Requirement: The system must be able to handle up to 1,000 concurrent users without a significant drop in performance. This sets a clear target for how robust the system needs to be.

Recap

  • The System Specification is the final output of the analysis stage.
  • It describes what the new system will do, not how it will do it.
  • It contains a detailed list of user and system requirements.
  • This document includes hardware and software requirements.
  • It serves as a guide for the design and development stages.
  • It acts as a formal agreement between the client and the developers.

Quick check

  1. Who are the two main groups of people that use the System Specification?2 marks

End-of-chapter exercise

Test yourself on the whole chapter. Work through these before moving on.

  1. State the four main methods used to gather information during the analysis of a system.4 marks
  2. A systems analyst is investigating a new payroll system for a company with 20 employees. The analyst decides to use interviews to gather information. Give two reasons why interviews are a suitable method in this scenario.2 marks
  3. Explain the difference between observation and examining existing documents as methods of analysis.4 marks
  4. Describe two problems that a systems analyst might discover when analysing a manual, paper-based office filing system.4 marks
  5. What is a System Specification and why is it important in the systems life cycle?3 marks
  6. A supermarket wants to introduce a new self-service checkout system. Compare the use of questionnaires and observation for finding out about the problems with the current checkout system staffed by cashiers.6 marks
  7. For a new school e-homework system, identify and describe two user requirements and one hardware requirement that would be included in the system specification.6 marks
  8. Explain why a systems analyst might use more than one method of investigation when analysing a system.2 marks
  9. A large online retailer is experiencing frequent crashes of its website during peak sales events. As a systems analyst, describe how you would investigate this problem, identifying the information you would need to collect.5 marks
  10. Discuss the contents of a System Specification. In your answer, you should describe at least four distinct sections or types of information it contains.8 marks

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