IMIS Contemporary IS Development

Theme: Development of Information Systems
Course: Higher Diploma
Module Title: Contemporary IS Development
Module Code: H33
Resources:

• Software: An Object Oriented Programming Language, CASE Tool and SQL compliant database.
• Students should have a working knowledge of the IMIS
• Code of Ethics and be able to understand and apply the ethical and legal concepts contained therein

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:

• Model business situations to inform the development process using accepted standards.
• Respond to a requirements specification by analysing and designing a contextually relevant solution.
• Examine the social and legal impacts of developing and implementing information systems and the role played by Information Systems professionals in addressing such issues.
• Determine effective strategies for managing information systems development.

MODULE AIMS:

To provide students with:

• A perspective on the problems in information systems development and their underlying causes, and what can be done to help avoid them. (A1)
• A review of contemporary system development approaches and methodologies. (A2)
• An introduction to the Unified Modeling Language (UML) and the Unified Software Development Process. (A3)
• Knowledge of the fundamental concepts of object orientation, and objectoriented systems development. (A4)
• An introduction to the concept of reusability and the potential for reuse in object-oriented development. (A5)

MODULE LEARNING OUTCOMES:
Students should be able to:

A1:

• Identify problems in information systems development and discuss their underlying causes. (LO1)
• Explain how different approaches and human factors can contribute to the software development process. (LO2)
• Appraise the wider ethical issues associated with information systems development and discuss their implications for computers and computerised information. (LO3)

A2:

• Review methodologies, frameworks and approaches for information systems development. (LO4)
• Discuss the problems of integrating new object-oriented information systems with legacy systems. (LO5)
• Compare hard and soft systems approaches. (LO6)

A3:

• Describe the fundamental concepts in the Unified Software Development Process (USDP). (LO7)
• Describe the support provided by the UML for the software development process. (LO8)

A4:

• Explain the fundamental concepts of object-orientation and the justifications for adopting an object-oriented approach to systems development. (LO9)
• Describe the steps involved in object-oriented analysis. (LO10)
• Describe the steps involved in object-oriented design. (LO11)
• Explain the need for identifying and specifying control in an application, and how to do so using UML statechart diagrams. (LO12)
• Describe the steps involved in moving from design to implementation. (LO13)
• Design, document and implement, using an object-oriented programming language, 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. (LO14)

A5:

• Discuss issues of reusability in the software development process. (LO15)

DETAILED MODULE CONTENT:

LO1: Problems in IS Development

• Problem perspectives: end-user, client and developer.
• Issues of quality and productivity.

LO2: Development Approaches and Human Factors

• Adopting a project life cycle.
• Benefits from prototyping and incremental development.
• User involvement and roles in projects.

LO3: Ethical Issues

• Consideration of the impact that a new information system will have.
• Project teams and professionalism; ethical behaviour.
• Legislation affecting an information systems development project.

LO4: Methodologies, Frameworks and Approaches

• Methodology for IS development: procedures, techniques, tools and documentation aids.
• Structured methodologies; object-oriented methodologies; the Unified Software Development Process (USDP).
• Dynamic Systems Development Method (DSDM): DSDM and Rapid Application Development (RAD); DSDM life cycle.
• Agile methodologies including Extreme Programming (XP), Test Driven Development, Refactoring.
• Open Source development: Open Source Initiative (OSI), Open Source Definition.

LO5: Legacy Systems

• Problems arising through interaction of systems built using different technologies.
• Integrating new object-oriented systems with non-object-oriented systems: object wrappers; screen scrapers.

LO6: Hard and Soft Systems Approaches

• Participatory Design; soft methodologies (for example, Checkland's Soft Systems Methodology (SSM) and Mumford's Effective Technical and Human Implementation of Computer-based Systems (ETHICS).
• How hard and soft methodologies differ.
• Combining hard and soft approaches (for example, using SSM as the front-end to a hard systems development approach).

LO7: Unified Software Development Process

• USDP phases: Inception; Elaboration; Construction; Transition.
• USDP disciplines: Business Modelling; Requirements; Design; Implementation; Test; Deployment; Configuration and Change Management; Project Management; Environment.
• Object-oriented analysis; object-oriented design.
• Iterative and incremental development.

LO8: The UML

• What is meant by a model; the distinction between a model and a diagram.
• Diagrams provided in the UML; the concept of a model in the UML.

LO9: Object-Orientation

• Fundamental concepts in an object-oriented approach: abstraction and encapsulation; event-driven systems and message passing; class and instance; object state; relationships between classes; inheritance and polymorphism.
• Benefits and limitations of object-orientation.

LO10:Object-Oriented Analysis

• Use-case driven development; use case realizations.
• Use cases and requirements specification; use case diagrams and use case descriptions.
• Definition of a Domain Model in the USDP; using class diagrams to illustrate a domain model: finding objects and classes; adding attributes to appropriate classes; adding associations; determining multiplicity.
• Attributes and state; link and association.
• Specification by contract.
• Algorithmic and non-algorithmic methods for describing operation logic.

LO11:Object-Oriented Design

• Object interaction and collaboration: developing object collaboration from use cases.
• The UML concepts of collaboration and interaction.
• Using UML sequence and collaboration diagrams to model object collaboration.
• Criteria for good design: coupling; cohesion; designing controller classes; message handling; assigning responsibilities to classes; Class, Responsibility, Collaboration (CRC) cards.
• Specifying classes: attributes, operations, visibility.
• Designing associations and navigability.
• UML interfaces and the realize relationship.
• Designing operations/methods.

LO12:Designing Control using Statecharts

• The notion of control in an application: for example, modelling state dependent variations in behaviour; the relationships between statecharts and other system models.
• Fundamental control concepts: state, event, transition, action; basic UML notation for drawing statecharts.
• Relevant example of constructing a statechart: for example, to model an object lifecycle or a human-computer dialogue.

LO13:Moving to Implementation

• Mapping designs to code: creating class definitions from detailed class diagrams: attribute definitions, method signatures; adding reference attributes; deriving the code for methods from interaction diagrams; implementing container/collection classes in code; adding accessor methods; adding constructors.
• Storing objects in files; serialization.
• Testing in an object-oriented system; unit testing: testing individual classes; integration testing: testing groups of collaborating classes, testing use cases; sub-system testing, system testing; acceptance testing.

LO14: System Building

Students should design, build and implement a simple system using object-oriented analysis and design methods, 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 object-oriented analysis models
• use of a Computer Aided Software Engineering (CASE) tool for at least part of the system building process
• production of an object-oriented design specification to include the following:
• detailed class diagrams
• interaction diagrams
• at least one relevant statechart diagram
• an appropriate user interface design incorporating input/output (I/O) design.
• coding the system and implementing it using an object-oriented programming language.
• 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.

LO15:Reusability

• What is reusable software; the arguments for reuse; idea (only) of reusable software components.
• Idea (only) of patterns: reuse in analysis; reuse in design.