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Systems Development Environment

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1 Systems Development Environment
Chapter 1 overview Introduce some topics we’ll cover in depth this term Chapter 1 Modern Systems Analysis & Design

2 Chapter 1 Learning Objectives
Define information systems analysis and design Describe different types of information systems Describe Systems Development Life Cycle (SDLC) Explain Rapid Application Development (RAD), prototyping, Joint Application Development (JAD), and Computer Aided Software Engineering (CASE) Describe agile methodologies and eXtreme programming Explain Object Oriented Analysis and Design and the Rational Unified Process (RUP) You should try to respond to each of these after reading the chapter.

3 Today’s Agenda What is SA&D? What Does a Systems Analyst Do?
Skills Participants in Systems Development What Goes Wrong Systems Development Methodology What is a Methodology For What Types of Systems is a Methodology Used? Traditional Systems Development Process (SDLC) Other Methodologies These topics are introduced/overviewed in the chapter, and provide a preview of what we will cover in more depth throughout the semester.

4 Information Systems Analysis and Design
The complex organizational process whereby computer-based information systems are developed and maintained. This course is about IS A&D: Complex and Organizational: Requires organizational analysis as much as knowing information technology Developed and Maintained: Encompasses analysis, design, implementation, and follow-up (support and maintenance) --> Hence, a long, comprehensive process What is a system? … see cartoon

5 What Does a Systems Analyst Do?
Studies the problems, needs, and opportunities of an organization Determines how people, methods, “computer technology,” and organizational methods can work together to best improve the business Responsible for developing efficient methods for capture, movement, processing, and storage of data Bridges technology and organization Central member of team (of various stakeholders) 1 & 2: The role of systems analyst is unique: nobody else charged with doing and coordinating these things, hence a SA is an organizational role. Chooses best sources of data 3: Makes sure data and information are useful and timely 4: Skills include?: o communication o technical and organizational knowledge o facilitation o organizing o leadership o Others? 5: Team is a key concept, since nobody can do all of this by herself

6 What Skills Does an Analyst Need? A Starter Set
Analytical skills Systems thinking Understanding business/organization via general and firm-specific knowledge Identifying problems/opportunities Analyzing and solving problems/opportunities

7 Systems Thinking: A General Depiction of a System

8 Systems Thinking: Fast-Food Restaurant

9 More Systems Thinking: O = f(I,P,S) Model of a System
Process Inputs Outputs Storage Classical processing model of a system What does this cause analyst to concentrate on? > Where start? -- outputs > What next? -- inputs > Then processes > Finally -- storage Build system in parts; focus on a subsystem; have multi-tier, client/server systems A system is a bunch of interconnected versions of these Obscures structure of storage and timing of events Incorporate discussion of, 1. Business Process Re-engineering Radical change in process Breakthrough improvements Disruptive technologies Don’t just automate, obliterate! 2. Data-Oriented Model of System (allows decoupling) Data capture and storage Data transfer/movement Data analysis Data presentation

10 More Systems Thinking: Design/Reengineering
C1 C2 C3 C4 C5 C6 System simplification concepts: Which system is more Cohesive Decoupled System A: C1 C2 C3 C4 C5 C6 System B:

11 What Is Systems Thinking?
Looking at a situation as a system of interacting components abstracting, decomposing Identifying problem and designing selecting, implementing a solution simplifying, reengineering internals of (i.e., processes) and interactions between components – including interfaces, using cohesion, decoupling

12 What Skills Does an Analyst Need? A More Complete Set
Analytical skills Systems thinking Understanding business/organization via general and firm-specific knowledge Identifying problems/opportunities Analyzing and solving problems/opportunities Technical skills Structuring requirements Designing databases, forms, reports, navigational interfaces Management skills Resource management Project management Risk management Change management Interpersonal skills Communicating Working in teams Facilitating groups Managing expectations

13 Who Are the Players in Systems Development?
User(s) Business manager(s) Steering committee Application programmers System programmers Database, network, and other technology specialists Security / auditing staff Human factors experts Documentation specialists So, who is on the team?

14 Analyst as a Member of System Development Team
Comment on / think about: What differentiates high performing teams from less successful ones? Which words make sense and which don’t? What does selling mean? o meeting needs o creating a market o competition o Proactive or reactive?

15 What Goes Wrong in General when Applying Skills in an Organization?
12. Too long 11. Inability to change business processes 10. Not allowing out-dated system components to be replaced 9. Excessive spending on “maintenance” 8. Functions delivered are out-of-date 7. Inadequate technology impedes rapid response to market 6. Users lose patience, but “home grown” solutions out-of-control 5. Critical data locked inside inaccessible systems 4. IS development priorities not consistent with business priorities 3. IS staff does not understand business or its needs 2. Management does not understand IS 1. IS unplanned or misdirected From Strategic IS Planning by Edwin E. Tozar, Butterworth-Heinemann, Boston, 1996, as quoted in Application Development Trends, May, 1996

16 Systems Development Methodology
A standard process followed in an organization to conduct all the steps necessary to analyze, design, implement, and maintain information systems How does a systems analyst assure quality work: through following a methodology. Standard process: A base/starting point for practice for the whole life cycle Why use a methodology? o Need for compatibility and consistency -- yet can be flexible o Need for efficiency o Proven methods -- and which can improve o Quality systems o Invest in training o Plug compatible analysts o Can’t be constraining or excuse not to evolve/improve, or … see cartoon

17 Methodology, Technique, Tool
Overall approach, usually within a framework or architecture Technique A way to do a specific task (e.g., interview, ERD, DFD, use-case diagram) Often graphical Tool An aid which helps to complete a technique (e.g., Visio, PowerPoint, MS-Project) or manage data used across techniques Methodology o The standard process of many steps (e.g., Anderson’s Foundation, EDSs RISE, or IDEF) o Each step may use many techniques or tools o Set of approved techniques and guidelines on when to apply Technique o A way to do a specific task (e.g., ERD, DFD, use-case diagram) o Often graphical o Follows rules Tool o An automated function which helps to (e.g., PowerPoint, Designer, MS-Project) > do a technique > manage data used across techniques

18 CASE: Examples of Tools
Case tools Software tools that provide automated support for some portion of the systems development process Examples of tools/functions supported Diagramming Generating screens and reports Give concrete example early to help anchor remaining discussion

19 What Is Analyzed Via Methodology?
Data (input/capture and storage) Information (output/presentation) Data flow (movement/transfer) Processing logic (manipulation/analysis) Note: These can be viewed as related but separate systems!

20 Types of Information Systems
Transaction processing MIS Business Intelligence DSS (Individual & Group) ESS/EIS Expert System Note: See Table 1-1 for differences characteristics development orientation (e.g., process or data) A systems analyst applies these skills in different ways to focus on different issues for different types of ISs. Some SA&D concerns for each type of system: Transaction processing SA&D issues: processing volume, interconnections, detailed security and validation MIS SA&D issues: summarization, timing, integration/consolidation of data sources DSS SA&D issues: information access, types of analyses, user interface ESS/EIS SA&D issues: summarization, user interface, information access, types of analyses Expert System SA&D issues: processing rules, decision logic, subtle processes Scientific/Engineering SA&D issues: graphical format, data manipulation Office Automation SA&D issues: work flow, efficiency, data access, personal and group productivity

21 Traditional Systems Development Methodology: Systems Development Life Cycle (SDLC)
Chapters 4-5 The SDLC is a way to group techniques and tools for our discussion. It follows a sequential learning process, but as we will see, we may not perform the tasks in this order. What are the issues? Too long until done Requirements/features creep Tendency to be too fixed and sequential, without proper overlap and feedback Chapter 16 Chapters 6-9 Chapter 15 Chapters 10-14

22 SDLC Planning Phase Identify, analyze, prioritize, and arrange IS needs

23 SDLC Analysis Phase Study and structure system requirements

24 SDLC Design Phase Logical design: functional features described independently of computer platform Convert recommended solution to system specifications Physical design: logical specifications transformed to technology-specific details

25 SDLC Implementation Phase
Code, test, install, and support the information system

26 SDLC Maintenance Phase
Systematically repair and improve the information system

27 Figure 1-12: Rapid Application Development
Some organizations try to speed up the life cycle by: o Combining initiation and planning and a preliminary analysis into an up-front phase o Iterating between design and construction as rapidly as possible o Combining some aspects of physical design with implementation into last pahse o Assuming maintenance is separate

28 Iterative/Agile Development
Repetition of refining steps Successively closer to goal Evolutionary/adaptive Continuous, self-adapting change simpler state to more complex or better state Focus on people not roles (people are talented and creative, not replaceable parts) – see Table 1-4 What are the general features of RAD or iterative development methodologies? You are encouraged to use iterative development in your project, but this is difficult since we will be learning techniques and tools in sequence. Some people view iteration more as a spiral

29 Spiral Development Design High-level Requirements Analysis Detailed
Many variations have been developed (see Chapter 19) The loops are the inner-two steps in the previous RAD diagram Note the explicit customer review points All methodologies include many of the same skills plus some unique ones Many methodologies in organizations are combinations of several pure methodologies Chapters 2 and 3 (next week) overview systems development and the skills required to be a player in a systems development project High-level Requirements Analysis Detailed Requirements Customer Review

30 Think of this as having a third dimension with larger circle at top, like a beehive.
This allows scalable development as new needs are identified, new units are brought on, learning occurs, more users are brought into the solution. It allows a simple, first solution to be implemented early, with progressively more functionality and hence users. Scalability is one of the most important goals of information systems development today. Deals directly with requirements/features creep

31 Figure 1-14: Phases of OOASD-Based Development

32 Figure 1-11: Prototyping: A Methodology or Component of Other Methodologies
Here is one specific RAD approach: prototyping An increasingly popular process, and one usually included in a methodology What issues do you anticipate? - When stop - Frustration - Change in whose in charge - Tools needed - When apply A form of iterative development

33 How Do Methodologies Change? Some Trends
Move from “art” -> “science” (tension) In-house development Outsourcing Purchased applications Modularized Web orientation

34 In Summary What is systems analysis and design?
What does a systems analyst do? What is a systems development methodology? Why use one? SA&D: The complex organizational process whereby computer-based information systems are developed and maintained. Systems Analyst: Determines how people, methods, “computer technology,” and organizational methods can work together to best improve the business Methodology: A standard process followed in an organization to conduct all the steps necessary to analyze, design, implement, and maintain information systems - an approach to problem solving relative to information needs in an organization Why: Address the complex organizational issues involved in solving such problems - e.g., agreeing on the problem to be solved, the steps to be taken (scope, timing, resources), the solution and its implementation, and the ongoing operation and maintenance of the system

35 Context Diagram of Data Flow Diagram (DFD)

36 Data Input Screen

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