What does the term ‘software crisis’ describe?

The software crisis describes the period in which software projects routinely ran late, cost far more than planned and delivered unreliable systems, because software development could not keep pace with rapidly growing hardware power.

Why did more powerful hardware make the software crisis worse?

Cheaper and faster hardware allowed far more ambitious systems to be attempted, and the informal methods that worked for small programs could not manage the complexity of the much larger systems that became possible.

How did the software crisis lead to the discipline of software engineering?

The scale of the failures showed that building software needed the same disciplined, planned approach as other branches of engineering, so lifecycle models, documented methods and formal project management were introduced.

State two consequences for an organisation whose software project fails.

The organisation loses the money already spent on the project and must carry on running an inadequate existing system, and it may lose customers to competitors whose systems work.

CCEA AS-Level Digital Technology 2650

Systems Analysis and Development Approaches

Topic overview The software crisis and the need for systems development User needs, time and cost Roles in a systems development team The purpose of analysis Fact-finding techniques Functional and non-functional requirements Data flow diagrams The waterfall model Rapid application development and Agile Resources, constraints and risks in a software project Project management, Gantt charts and critical path analysis Version management

Design, Development and Testing

Topic overview The purpose of systems design Storyboarding the user interface Prototyping the interface and the data model The development stage: turning a design into working code Why testing runs throughout development Levels of testing: unit and integration System testing Acceptance testing Alpha and beta testing The purpose and components of a test plan Types of test data

Implementation and System Security

Topic overview The purpose of system implementation Direct and parallel changeover Pilot and phased changeover User documentation Technical documentation Data conversion The purpose of system maintenance Corrective, adaptive and perfective maintenance Archiving data Backup and recovery Full, differential and incremental backups Disaster recovery plans

Programming

Topic overview The purpose of a computer program The integrated development environment Translation: compilers, interpreters and assemblers The stages of compilation and linking Algorithms, pseudocode and syntax Variables, constants and data types Sequence and selection Iteration: count-controlled and condition-controlled loops Flowcharts and algorithm representation Objects, classes and methods Inheritance and evaluating the object-oriented approach

Data, Information and Data Representation

Topic overview Bits, bytes and units of storage How many values a given number of bits can hold Converting decimal to binary Converting binary to decimal Two's complement and negative numbers Character sets: ASCII and Unicode Data, information and knowledge Factors affecting the quality of information Validation: range, type, length and presence checks Validation: format checks and lookup checks Check digits and the Modulus 11 method Batch totals, verification and the limits of checking

Computer Architecture and Processing Systems

Topic overview The processor, the clock and the registers The fetch-execute cycle Buses, input and output controllers and ports Main memory: RAM, ROM and addressing Cache memory and the memory hierarchy Factors that affect processing speed The need for secondary storage Magnetic, optical and flash storage media Choosing secondary storage for common applications Batch, real-time and transaction processing Automatic teller machines and point of sale terminals Smartphones: input, output and processing

System Software, Application Software and the User Interface

Topic overview User interfaces: WIMP, command line and forms dialogue Choosing and evaluating a user interface Inputting text, sound and video The purpose of an operating system How an operating system manages memory and processes Types of operating system Utility programs The need for data compression, lossless and lossy Zipping and archive files Common data file formats Application software: generic and special purpose Obtaining and delivering software

Web Technology and Multimedia

Topic overview The internet, the World Wide Web and web standards URLs, HTTP and the request-response cycle Domain names, DNS and IP addresses Web browsers, search engines, cache and cookies Web servers, hosting, ISPs and file transfer Intranets and how an organisation uses one Creating web pages with HTML HTML tags for text, lists, images and links Styling pages with CSS Multimedia assets in a web page Client-side and server-side processing Security over the internet: encryption, HTTPS and certificates

Systems Analysis and Development Approaches

12 subtopics
36 things to know
AS Unit 1

What Systems Analysis and Development Approaches covers

Systems Analysis and Development Approaches is examined in Unit AS 1, Approaches to Systems Development. It covers the software crisis and the need for systems development, user needs, time and cost, roles in a systems development team, the purpose of analysis, fact-finding techniques, functional and non-functional requirements, data flow diagrams, the waterfall model, rapid application development and Agile, resources, constraints and risks in a software project, project management, Gantt charts and critical path analysis and version management.

Where it is assessed

AS Unit 1

Approaches to Systems Development.

Check the CCEA specification ↗

The 12 subtopics

Each one has its own page. CCEA AS Digital Technology students sit this topic in the first year.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Key term

Explain why poorly written software stays expensive long after it is delivered.

Key term

Why is time the dominant factor for a system tied to an external date?

Key term

Explain why involving users throughout development saves money overall.

Key term

Why is analysis completed before design begins?

Evaluation

Give two disadvantages of questionnaires.

Key term

Why can a system that meets all its functional requirements still be rejected?

Key term

What is the purpose of a data flow diagram?

Key term

What is the difference between a context diagram and a level 1 DFD?

Key term

Produce a context DFD in words for a simple scenario: a dentist's practice recording appointments.

Key term

Why does the waterfall model suit a fixed-price contract?

Key term

Why does a project manager use a Gantt chart and critical path analysis together?

Key term

What is the main role of a systems analyst?

Evaluation

Give two advantages of Rapid Application Development.

Key term

Name the three main elements in the organisation of a software project.

Key term

Why is version management essential when several programmers work on one system?

Numbers

Where was the term ‘software crisis’ first used?

Key term

Name three tasks a systems analyst carries out during analysis.

Process

What is the purpose of the analysis stage of systems development?

Key term

Describe how an interview is used as a fact-finding technique.

Key term

What is a functional requirement?

Key term

Describe the waterfall model of systems development.

Evaluation

Give two disadvantages of Rapid Application Development.

Key term

Give three examples of human resources on a development project.

Key term

What is project management?

Key term

What is meant by locking a file?

Key term

Give three symptoms of the software crisis.

Key term

Name the three main factors that shape any systems development project.

Key term

What is the main role of a project manager?

Key term

Name the three parts that make up any computer system.

Evaluation

Give two advantages of interviews over the other fact-finding techniques.

Key term

Give one non-functional requirement for a payroll system, and justify it.

Process

Name the stages of the waterfall model in order.

Key term

Describe the Agile approach to systems development.

Key term

What is meant by a constraint on a project?

Key term

Name four activities a project manager performs.

Key term

What is a branch?

Take Systems Analysis and Development Approaches further

The same content, four other ways.

Commonly confused

Pairs that lose marks when they are blurred together.

Constraint vs Risk
Constraint: a limit known at the outset that the plan must fit inside. Risk: a possible future event the plan must be ready for.
Interview vs Questionnaire
Interview: a two-way conversation with a single person, so an answer can be followed up. Questionnaire: a fixed set of written items sent to many people at once.
Observation vs Document sampling
Observation: watching people at work to see what really happens. Document sampling: examining the forms and records to see what data is actually held.

Questions from this topic

Each one with the model answer underneath.

1
What does the term ‘software crisis’ describe?
Model answer
The software crisis describes the period in which software projects routinely ran late, cost far more than planned and delivered unreliable systems, because software development could not keep pace with rapidly growing hardware power.
2
Where was the term ‘software crisis’ first used?
Model answer
The term ‘software crisis’ was first used at a NATO conference on software engineering held in Germany in 1968.
3
Give three symptoms of the software crisis.
Model answer
Projects overran their deadlines, projects exceeded their budgets, and the software delivered was often unreliable or did not do what the user had asked for.
4
Why did more powerful hardware make the software crisis worse?
Model answer
Cheaper and faster hardware allowed far more ambitious systems to be attempted, and the informal methods that worked for small programs could not manage the complexity of the much larger systems that became possible.
5
How did the software crisis lead to the discipline of software engineering?
Model answer
The scale of the failures showed that building software needed the same disciplined, planned approach as other branches of engineering, so lifecycle models, documented methods and formal project management were introduced.
6
State two consequences for an organisation whose software project fails.
Model answer
The organisation loses the money already spent on the project and must carry on running an inadequate existing system, and it may lose customers to competitors whose systems work.

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Systems Analysis and Development Approaches

Design, Development and Testing

Implementation and System Security

Programming

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Systems Analysis and Development Approaches revision questions

Is Systems Analysis and Development Approaches examined at AS in CCEA Digital Technology?: Yes. It sits in AS Unit 1, which you take in the first year, so it is on the AS paper as well as counting towards the full A level.
What does Systems Analysis and Development Approaches cover in CCEA AS-Level Digital Technology?: 12 subtopics: the software crisis and the need for systems development, user needs, time and cost, roles in a systems development team, the purpose of analysis, fact-finding techniques, functional and non-functional requirements, data flow diagrams, the waterfall model, rapid application development and agile, resources, constraints and risks in a software project, project management, gantt charts and critical path analysis and version management. Each one has its own page with questions and model answers.
How is Systems Analysis and Development Approaches organised?: By the CCEA 2650 specification, subtopic by subtopic, so it matches the order you are taught it in.

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