Miguel Nunes email: j.m.nunes@sheffield.ac.uk Information Systems Project Management IS Development Methodologies (2) Miguel Nunes email: j.m.nunes@sheffield.ac.uk

Aims of this Session To identify and discuss the nature and role of Information Systems Methodologies. To present the different types of modern methodologies, namely structured, agile and object oriented methodologies. To present SSADM as a structured methodology and RAD as an agile iterative methodology.

Aims and Objectives Aims The main aim of this module is to consider the role of information systems within the organisation and to provide an appreciation of the rigorous methods that are needed to manage projects that analyse, design develop, install and maintain these computer based information systems.

Information System Definition An Information System can be defined technically as a set of interrelated components that collect, process, store and retrieve, and distribute information to support decision making, co-ordination and control in an organisation. An information system is an organisational and management solution, based on information and communication technology, to a challenge posed by the environment.

Components of an Information System

Information Systems Thinking The Information System must be developed considering the organisation as a whole rather then for a collection of functions in isolation. Organisations are open systems and therefore the relationship between the organisation and its environment is important. Organisations are human activity systems and people often have conflicting objectives, perceptions and attitudes. Human activity systems constantly evolving and therefore unpredictable. There is no such thing as a repeatable experiment.

Information System Definition A system that assembles, stores, processes and delivers information relevant to an organisation (or socio-technical environment), in such a way that the information is accessible and useful to those who wish to use it as required by their activity practices, including managers, staff, customers, suppliers, other business partners and citizens. An IS is therefore an human-activity system which may or may not involve the use of IT based systems.

Information System Development A system that assembles, stores, processes and delivers information relevant to an organisation (or socio-technical environment), in such a way that the information is accessible and useful to those who wish to use it as required by their activity practices, including managers, staff, customers, suppliers, other business partners and citizens. Question here are: How do we identify the people that use and need the IS? How do we understand their work practices? How do we identify their information needs? How do we respond to all of these questions so that the organisation benefits from the IS?

IS Development Methodologies “ a coherent collection of concepts, beliefs, values and principles supported by resources to help a problem-solving group to perceive, generate, assess and carry-out in a non-random way changes to the information system” (Avison and Wood-Harper, 1990) 1. Set of methods for tackling the different problems involved. 2. Sound theoretical basis in order to understand why and when to use the methods.

IS Development Methodologies A collection of procedures, techniques, tools and documentation aids that help developers in their efforts to understand users, their socio-technical environment, their work practices and their information needs.

USER versus SYSTEMS DEVELOPER developer needs to understand the users environment; users often don't know enough about the capabilities of computer systems to specify in an accurate way; in addition there is the problem of the requirements of the system continually changing throughout the analysis and design process.

less extensive but more detailed. Systems Development ? discovering detailed business requirements by a detailed analysis of business data; increasing business understanding since the business is described in terms of simple easy to read diagrams; enables better negotiation of systems requirements between different user groups and analysts; provides a framework for identifying and evaluating opportunities to enhance the business- problems identified which were not previously evident; common framework of concepts and terminology.... less extensive but more detailed.

IS Development Methodologies A collection of procedures, techniques, tools and documentation aids that help developers in their efforts to understand users, their socio-technical environment, their work practices and their information needs. IS Methodologies consist of phases whish will guide the systems developers in what to do and their choice of techniques that might be appropriate at each stage. Each phase may contain subphases. These phases (or stages, or main activities) form the IS Project and help manage, control and evaluate the project.

IS Development Methodologies However ……. These 4 stages of start-up, development, completion, and operational may be instantiated in VERY DIFFERENT WAYS depending on the IS Methodology selected.

IS Development Methodologies There are 3 main types of methodologies in use today: Structured Approaches Agile Methodologies Prototyping approaches Incremental approaches Object Oriented Approaches

Structured Methodologies Structured Approaches offer a set of techniques and tools to carry out the information systems development work within a defined framework. The framework defines an overall structure (sequence of phases) that ensures a more consistent and complete approach to the work. The framework allows the progress of the work to be fully charted and that there are no sudden unconnected and unexplained jumps between phases.

Structured Methodologies Main characteristics of structured methodologies: Separation of logical and physical analysis; Emphasis on data (data modelling and data flow modelling); Diagrammatic Representation; Documentation reviewed and signed off throughout the analysis, design and development. Use involvement (but limited); Compliance to framework; Long periods of development ….

Agile Methodologies Agile Methodologies are known as lightweight development methods based on rapid development cycles and flexible response to changes in requirements. Based on one basic idea: Requirements are so difficult to define that they must evolved during the period of development. This is based on 80:20 Pareto principle.

Agile Methodologies Agile Methodologies are also based on the following principles: Individuals and interactions over processes and tools; Working software over comprehensive documentation; Customer collaboration over contract negotiation; Responding to change over following a plan.

Agile Methodologies There are two types of agile methodologies based on two types of evolutionary development: Iterative Evolutionary approach based on repetitive cycles of development and successive revision of requirements during each iteration. Based on the principle of prototyping. Incremental Evolutionary approach that involves breaking the application down into small components which are then implemented and delivered in sequence. C1 C3 SW App C2 C4

Object Oriented Methodologies Waterfall, Structured Approaches and many of the early Prototyping methodologies were based on the concept of function. Functions represent work practices, i.e. what people do and what data they need to do it. That is data models: Order Line Sales Person Customer Sales Order Product made of part of order for ordered by takes taken by placed by places

Understanding Object Orientation

Object Orientation (OO) Object orientation is a mind-set think in terms of objects objects represent something in the real world Differs from other models such as process and data modelling involves modelling data and processes (functionality), but in a different way data and functionality encapsulated into an object (not treated separately)

What “things” can you see in this picture What “things” can you see in this picture? What characteristics and behaviour do these have?

Object Orientation (OO) “Object-oriented programming is a method of implementation in which programs are organised as a co-operative collection of objects, each of which represents an instance of some class, and whose classes are all members of a hierarchy of classes united via inheritance relationships.” (Avison & Fitzgerald, 2003: 241)

Objects and entities An Object is an abstract representation of an instance of an Entity. It is something to which actions are directed. Objects have identity – the name of the object state – names of properties that describe an object (attributes) and values of those attributes at some point in time. behaviour - the set of operations which represent the behaviour of the entity. The procedure that implements an operation is called a method. Objects are like entities but also exhibit behaviour

Objects and classes Class collection/categorisation of similar objects classes are templates for making objects classes have attributes but no values classes define behaviour in terms of operations an object is an instance of a class Person name age addr height eat() sleep() walk() goToWork() talk() attributes operations INF311-6110 Information Systems Modelling

Inheritance Classes can be organised into a hierarchy Animal Amphibian Mammal Reptile Lion Classes can be organised into a hierarchy some types are more general/specific than others child “is a kind of” parent Specific types can inherit characteristics of more general types Objects can be instances of many types simultaneously UML also refers to this as generalisation INF311-6110 Information Systems Modelling

Encapsulation Processing/ operations Data Interface Egg structure of an object Internal processing and details of data are hidden (information hiding) Interface presents “face” to outside world.

Message passing In a system, objects work together by sending messages to each other Passing messages sending object requests to perform an operation receiving object knows what to do and performs operation messages passed through interfaces TV remote messages include change channel increase volume ???? INF311-6110 Information Systems Modelling

Message passing A network of objects make up a system or program begins with event from outside which triggers an object that object initiates another object … Event Message A B C E D F

Main OO concepts Abstraction Inheritance Polymorphism Encapsulation Message sending Associations Aggregation 3 “pillars” of OO

IS Development Methodologies “ a coherent collection of concepts, beliefs, values and principles supported by resources to help a problem-solving group to perceive, generate, assess and carry-out in a non-random way changes to the information system” (Avison and Wood-Harper, 1990) 1. Set of methods for tackling the different problems involved. 2. Sound theoretical basis in order to understand why and when to use the methods.

This module’s question: “We know why projects fail, we know how to prevent their failure -- so why do they still fail?“ Cobb (1995) Old question!???

Project Management What needs to be done ? What has happened ? What is happening ? What is going to happen ? What needs to be done ? How are we going to do it ? When are we doing it ? Who is going to do it ? What is the quality of our work (product) ? What are the risks involved ?

Project Management Planning and Organising Estimating (What and How) Estimating ( When and Who) Scheduling and Monitoring ( awareness of progression, remediation action, quality assurance)

Planning and Organising (What and How) Understanding requirements; Selecting a methodology; Determining deliverables and milestones; Determining verification and validation checks.

To Sum up ... What needs to be done ? IS Methodologies support Project Managers in understanding what needs to be done and avoid frustration at the end of project. What needs to be done ?