IMIS Information Systems Building

Theme: Development of Information Systems
Course: Diploma
Module Title: Information Systems Building
Module Code: D26
Resources:

• Software: Visual Basic, Access.
• Spreadsheet Package. CASE Tools.

Assessment:

By a single 3-hour externally set examination paper

CATS Equivalent: 200 Notional Hours:

• 80 Hours Structured,
• 120 Hours Directed Self-Study

SPECIFIC COURSE AIMS AND LEARNING OUTCOMES:

• Explain the need for a disciplined approach to all stages of Information Systems (IS) development, with emphasis on those techniques used within requirements definition.
• Describe the role of user participation in the IS development process, and explain how prototyping may help this process.
• Demonstrate the communication and problem solving skills required by Information Systems professionals in the workplace.

MODULE AIMS:

To provide students with:

• An overview of the development process, managed in the context of the systems life cycle, for designing and implementing an information system. (A1)
• Knowledge of the structured models commonly used within each stage of the development of an information system, and the structured methods and techniques for specifying, documenting and constructing them. (A2)
• A perspective of information systems building in an organisational context that includes working in a project-based environment, human and technical aspects of design, and quality-assured processes. (A3)

MODULE LEARNING OUTCOMES:
Students should be able to:

A1:

• Describe a simple system in terms of basic system principles, and describe the relationship between people, process and information technology. (LO1)
• Describe the stages in the Systems Development Lifecycle (SDLC) that most systems development projects follow and alternative software development processes (LO2)

A2:

• Explain the need to specify and document a computerised information system from the three modelling perspectives: process, data and behaviour. (LO3)
• Identify functional and non-functional system requirements and describe methods for specifying them. (LO4)
• Describe methods used for modelling system process and system data. (LO5)
• Describe the major elements of system design. (LO6)
• Explain why testing should be regarded as a significant part of an information systems development project, and identify the different types of testing that may be carried out during the SDLC. (LO7)
• Design, document and implement from a requirements specification, a relatively simple information system that incorporates a Graphical User Interface (GUI), and the facility for the persistent storage of data from several entities using either a database package or files. (LO9)

A3:

• Describe the supporting activities needed in the systems development process. (LO8)
• Describe the role of the end-user in the stages of systems development. (LO10)
• Describe and compare organisational strategies for managing the changeover to a new information systemfrom an old system. (LO11)
• Give an account of the ethical, moral and legal issues facing the information systems professional. (LO12)
• Describe data entry controls and controls for managing threats to an information system. (LO13)

DETAILED MODULE CONTENT:
LO1: The System Development Environment

• System environment, system boundary and subsystems; how people use information technology and processes in their work; the basic components of computer-based information systems.

LO2: Systems Development Lifecycle

• Stages of the SDLC and their major activities and deliverables: Initiation; Feasibility study; Systems analysis; Systems design; System implementation; System changeover; Review and Maintenance; the linear/waterfall lifecycle.
• Bespoke development; off-the-shelf packages; enduser development.
• Problems with the linear/waterfall lifecycle; incremental/ staged development; prototyping in system development; Rapid Application Development (RAD); Dynamic Systems Development Method (DSDM); evolutionary design and the spiral model (Boehm); quality assurance in the development process.

LO3: Why We ModeI Information Systems

• Modelling the three aspects of a system: processes, data and relationships, and behaviour.
• Modelling information systems with different characteristics: process-oriented systems; event-driven systems; real-time systems.
• Validating and verifying system models: checking the syntactic accuracy and the semantic accuracy of each model.
• Maintaining consistency of information between models: cross-validating system models.
• Distinction between a physical model and a logical model.
• Modelling existing systems and modelling new systems; green-field and brown-field development; legacy systems: creating new front-ends; understanding and capturing information about the current system; re-engineering and forward engineering.

LO4: Systems Analysis: Requirements Determination

• Contrast between modelling an existing system and modelling the requirements for a new system.
• Problem definition; feasibility analysis.
• The analysis phase of systems development; requirements determination and analysis.
• Determining requirements: gathering information and data collection methods.
• Functional and non-functional requirements.
• Expressing functional requirements as a list of system features by short, high-level descriptions.
• Expressing functional requirements with Use Cases.

LO5: Systems Analysis: Modelling Methods and Techniques

• Contrast between using Data Flow Diagrams (DFDs) for modelling the flow of information between processes and Flow Charts for modelling the sequence of control between processes.
• Context diagrams; physical DFDs; logical DFDs; levelling DFDs.
• Describing data: the Chen Entity-Relationship Diagram (ERD), identifying candidate entities; distinguishing between an entity and an attribute of an entity; relationships between entities; drawing an ERD using the Chen notation; resolving many-tomany relationships.
• Process descriptions.
• Hard and soft methods and techniques in systems analysis; human activity systems; Checkland's Soft Systems Methodology (SSM): rich pictures, outline of stages in SSM, using SSM as a 'front end' to more traditional structured development methodologies.

LO6: System Design

• Creating the system specification; transition from analysis to design.
• Program and module design: creating subsystems; structure charts and structured design; completing module definitions.
• User interface design: as part of the field of Human-Computer Interaction (HCI); interface elements, forexample, forms, dialogues and menus.
• Input design: user input and data capture techniques: for example, on-screen forms, files, bar-code scanning; data validation.
• Output design: specifying how production of reports will occur, for example, source of data (which records and fields); processing requirements for example, aggregation, calculation and sorting; and whether output to screen, printer, file or database.
• Logical database design: logical data structures; relations and tables in the relational database model.
• Physical design:
• converting a logical record structure to a relational database definition
• specifying access requirements
• packaging the program design into load modules
• system deployment.

LO7: System Development Testing

• The purpose of testing: checking that the requirements have been implemented; identifying errors or bugs.
• Test specification; systematic testing using a test script; test plan.
• Relating analysis and design activities to testing activities: the V-model.
• Testing carried out by the developer; testing carried out by the user, for example, user acceptance testing.
• Quality assurance: reviews, inspections and walkthroughs.

LO8: Supporting System Development

• Project management activities and tools.
• Development teams; inclusion of end-users in the stages of development work.
• Configuration management: builds and release versions; alpha releases and alpha testing; beta releases and beta testing.
• Using CASE tools; component CASE tools; integrated CASE tools.

LO9: Information Systems Building

• Students should design, build and implement a simple system starting from a set of system requirements. Note that this is not intended as an exercise in requirements determination, but as an exercise in specifying and constructing a system from a given set of requirements. This will typically involve:
• the production of relevant systems analysis models
• use of a Computer Aided Software Engineering (CASE) tool for at least part of the system building process
• production of a design specification to include the following:
• program structure chart
• Structured English for at least one module
• an appropriate user interface design incorporating input/output (I/O) design
• coding the system and implementing it.
• Students should be encouraged to build incrementally with the first build dealing with input and output to the screen, the second build dealing with file I/O or database I/O.

LO10: Role of the End-user

• Participation of the end-user in stages of the developmentprocess: for example, use of prototyping in systems analysis; opportunities for end-user development; acceptance testing.

LO11: Selecting a Changeover Method

• Factors to consider: cost; time; quality of new system after changeover; impact on customers; impact on employees; technical issues.
• Alternative methods for changeover: immediate cutover; parallel running; phased implementation; pilot system.
• Using combinations of changeover methods.
• Deployment planning.

LO12: Ethical, Legal and Moral Constraints on Information Systems

• Computer ethics: ethical behaviour as morally acceptable conduct; stakeholders; codes of professional conduct (for example, IMIS Code of Ethics); privacy and confidentiality.

LO13: Data Controls and Information Systems Security

• Validation of data entry: controls for interactive transaction input, controls with offline input.
• Data security: authentication, authorisation, privacy, and data integrity.
• The need for controls upon information systems: different types of threats, control strategies, types of controls