The Essentials of Analysis and Design. Mehran Rezaei

Transcription

1 The Essentials of Analysis and Design Mehran Rezaei

2 Stakeholders: Players in the Systems Game A stakeholder: any person who has an interest in an existing or proposed information system. technical workers nontechnical workers internal workers external workers Information workers: workers whose jobs involve the creation collection processing distribution use Knowledge workers: a subset of information workers responsibilities are based on a specialized body of knowledge of Information, 60% of Labor in the U.S. 2

3 System Owners an information system s sponsor and executive advocate, usually responsible for funding the project of developing, operating, and maintaining the information system Managements Large Medium small Bottom Line: Cost, benefits, and value to the system Mid to Executives Mid to supervisors 3

4 System Users System users: a customer who will use or is affected by an information system on a regular basis capturing, validating, entering, responding to, storing, and exchanging data and information. Main concerns: Ease of use ease of learning perceived usefulness 4

5 Internal System Users Clerical and service workers Technical and professional staff Supervisors, middle managers, and executive managers 5

6 External System Users Customers Suppliers Partners Employees Remote users - users who are not physically located on the premises but who still requires access to information systems. Mobile users - users whose location is constantly changing but who require access to information systems from any location 6

7 System Designers and System Builders technology specialists System designer translates system users business requirements and constraints into technical solution designs the computer databases, inputs, outputs, screens, networks, and software to meat system users requirements System builders constructs information systems and components based on the design specifications generated by the system designers. 7

8 . Systems Analysts Studies the problems and needs of an organization to determine how people, data, processes, and information technology can best accomplish improvements for the business programmer/analyst (or analyst/programmer) includes the responsibilities of both the computer programmer and the systems analyst business analyst focuses on only the non-technical aspects of systems analysis and design 8

9 Where Do Systems Analysts Work? 9

10 Skills Needed by the Systems Analyst Working knowledge of information technology Computer programming experience and expertise General business knowledge General problem-solving skills Good interpersonal communication skills Good interpersonal relations skills Flexibility and adaptability Character and ethics 10

11 The Systems Analyst as a Facilitator 11

12 Simple Systems Development Process Requirements Design Code Test 12

13 Systems Analysis Phases Systems Owners Planning Problem Statement Scope & Vision Problem Analysis Objectives Requirements Analysis BRD Documentation Logical Design Data Model Data Flow Design Or Use Case Diagram 13 Class and Activity Diagram

14 Understand the Problem Domain Goal Business and Systems Analysts get together with Business Owners and Users to find a common ground vocabulary Knowledge List all the things that system currently stored data about (files, forms, databases) Define each in business terms e.g., an order is a transaction where customer tries to buy a product Process Define each business event for which a business response is implemented e.g. a customer places a new order or cancels an order Interface Define all the locations of the servers and users of the system Also interface between current information system and other systems Context box System itself is a black box Inputs are what the system responds and reacts to Outputs are the outcome of the system like reports 14

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16 Identify and Express the Requirements Express the requirements into Functional Non Functional Performance, Ease of learning and use Budget cost, cost savings Timetables and deadlines Quality management 16

17 Requirements Analysis Phase What capabilities should the new system provide for its users? What data must be captured and stored? What performance level is expected? What are the priorities of the various requirements? 17