Unit 3: Software Development

AREA OF STUDY 1 - Systems analysis and design

SoD Unit 3 Outcome 1 - 50% of semester SAC marks

Analyse an organisation's networked information system and propose physical design specifications to improve it. Includes a written report (including documentation of analysis and design) (80%) and a labelled visual representation of a networked information system. (20%)

Key knowledge

1. Types of information systems, their objectives and where they are used
2. Goals and objectives of information systems
3. Types of networks
4. Pros and cons of different network topologies
5. Operating systems
6. Network operating systems
7. Network cards
8. Network cables and wireless
9. Routing devices - routers and switches
10. Network protocols
11. Why organisations change information systems.
12. Threats to data and info - deliberate & accidental actions, and technical failures; and viruses, trojans, spyware, hacking and denial of service.
13. Protecting data and info - devices and procedures;
14. Systems development life cycle (SDLC) - Waterfall model
15. Alternative software development models: RAD, prototyping, and Agile
16. analysis phase of the SDLC
17. Representing the logical designs of networked information systems, including context diagrams, data dictionaries
18. Data flow diagrams,
19. Collecting data for analysis - observation, surveys, interviews, reading documentation, logs
20. Design phase of the SDLC - deciding the people, procedures, data and equipment needed to implement a logical design
21. Tools for representing the physical designs, including system flow charts, structure charts
22. Functions and characteristics of hardware and software components, including security devices
23. Physical design specifications for the input, processing and output requirements that will enable a new information system to achieve its goals.

SD KK3.1.04 - types of network topologies

Topology is the logical shape of a networ's cabling.

• star - a central switch branches out to many computers
• bus - a single cable has offshoots leading to computers. Cable breaks will bring down all the computers, like a bad bulb in a string of christmas tree lights. Prone to congestion if too many PCs are attached.
• tree* - a combination of star and bus. Most networks use tree topology.
• ring* - each computer has an "upstream" and a "downstream" neighbour. Network signals travel in one direction around the ring. Uses Token Ring protocol to avoid network collisions. Very rare, expensive, and relatively slow.

KK4.2.04 - network operating systems and network architecture and components

• Network operating system (NOS) - software runs on the file server to control the network, e.g. Novell's Netware and Microsoft's Windows Server 2003.
• network interface card (NIC) - connects a computer to the network
• switches - used to branch a network cable to many PCs, or connect network segments. Also see hub.
• routers - used to direct packets from source to destination, and to protect LANs from outsiders, and to divide LANs into protected sections.
• servers - run the NOS, are the heart of most networks
• protocols - rules for communicating across a network. You need to know TCP/IP and Ethernet.

SD KK3.1.12 - threats to data

Threats include:

• viruses, spyware, trojans
• unauthorised access by employees or outsiders
• tampering with files
• failure to follow file management procedures (deliberately or accidentally)
• equipment failure/damage
• incompetent or disgruntled employees
• incomplete or unenforced security measures (e.g. weak passwords)

AREA OF STUDY 2 - Software development

SoD Unit 3 Outcome 2 - 50% of semester SAC marks

Produce a software module (not necessarily a full-blown application) suitable for use on a portable computing device (e.g. laptop, mobile phone, PDA, games console) [80%]. Verify its performance. Explain how the program has taken into account an ethical dilemma or a legal obligation. [20%]

Key knowledge

1. Stages of software development - the SDLC again - design, development and testing are mandated.
2. Handling and managing files, including security, archiving, backups, disposal
3. Data types, data structures and data representation
4. Data validation
5. Types and specifications of portable computing devices, including PDAs, mobile phones, laptops, gaming consoles
6. Data tables
7. Algorithms
8. An overview of flow charts, pseudocode, N-S diagrams, object descriptions and a detailed understanding of one of them
9. Internal documentation - why and how
10. Naming conventions for program elements
11. Legal obligations and ethical issues for programmers
12. Creating good user interfaces
13. Criteria for evaluating software: incl. effectiveness, efficiency, stability, reliability, usability, maintainability
14. How to check that programs meet design specifications, including creating good test data
15. Essential hardware during programming.

Unit 4: Software development

SoD Unit 4 - Area of Study 1 - Software engineering

Outcome 1 - 50% of semester SAC marks

- Produce purpose-designed software that takes into account a networked information system objective and the needs of end-users. Use the same programming language used in unit 3. Include internal documentation. 70%
- User documentation and explain how custom software may cause conflict between program developers and end-users in a test or written report. 30%

Greyed out items are repeats of earlier topics.

Key knowledge

1. Types of information system goals and their objectives
2. Stages of software development - again - all 7 steps - including Documentation!
3. Organising files to suit particular software needs, including serial, sequential and random access
4. Factors affecting data access, including file size, storage media, organisation of files
5. Naming conventions for program elements
6. Syntax of a programming language
7. Factors that affect software design: including user interface, end-user needs, processing efficiency, development time
8. Data structures used to organise and manipulate data - their types and uses
9. How to representing an algorithm
10. Testing strategies
11. Forms of user documentation, incl. printed, CD, website
12. Types of user documentation, including quick start guide, tutorial, content sensitive help and manual
13. Uses and purposes of programming utilities
14. The relationship between the software developers and end-users.

SoD Unit 4 - Area of Study 2 - Systems engineering: Development, implementation and evaluation

SoD Unit 4 Outcome 2 - 50% of semester SAC marks

Propose and justify strategies for managing, developing, implementing and evaluating a new networked information system that will operate in a global environment - a test or written report.

Key knowledge

1. How organisations use information systems in a global environment
2. Advantages and disadvantages for organisations and society in using information systems in a global environment
3. Development phase of the SDLC - using the physical design to acquire/develop hardware and software, gathering necessary personnel, and assembling and testing the new information systems
4. Project management tools and techniques to schedule and monitor tasks, assign resources, identify milestones and determine contingency plans
5. Technical, human, procedural, economic and management factors influencing the acquisition of hardware and software components (note - "acquisition", not "choice of")
6. Testing: to make sure components work as intended and to gain acceptance of the networked system
7. Implementation phase of the SDLC, including user documentation, designing and conducting training programs, preparation of disaster recovery plans and the changeover to new systems
8. Types of system support documentation to help end-users implement a new information system
9. Training requirements - including location of training and nature of training
10. Implementation methods, including direct, phased, pilot and parallel conversions
11. Protecting and securing stored and communicated data and information;
12. Evaluation phase of the SDLC, including determining if the information system is fulfilling its design specifications
13. Criteria and methods to evaluate the performance of an information system.