welcome to cmpe003 personal computer concepts: hardware and software

Welcome to CMPE003 Personal Computer Concepts: Hardware and Software

Winter 2003UC Santa Cruz

Instructor: Guy Cox

January 23, 2003 2

Assignments

Assignment #6 – The Last One Due March 12, 2003

Spreadsheets – (MS Excel) Generate a monthly budget spreadsheet

http://www.soe.ucsc.edu/classes/cmpe003/Winter03/hw6_spreadsheet.html

January 23, 2003 3

Final Project

Due no later than March 19, 2003 You can turn in earlier..

Power Point presentation 4 pages Extra points for special effects, animations

Turn in on a floppy/CDROM

http://www.soe.ucsc.edu/classes/cmpe003/Winter03/finalproject.html

Systems Analysis and

Design:

The Big PictureChapter 15

January 23, 2003 5

Objectives

Define the terms system, analysis, and design Describe the principal functions of the systems

analyst List and describe the phases of the systems

development life cycle Describe the various data gathering and analysis

tools Describe a selection of systems design tools Explain the concept of prototyping Explain the role of the maintenance task in the

systems development life cycle

January 23, 2003 6

Systems Analysis and Design: What is it?

System organized set of related components

established to accomplish certain task Natural Systems

Cardiovascular system Planned and placed by people

Water system Computer system

A system that has computers as one of its components

January 23, 2003 7

Systems Analysis and Design: What is it?

Systems analysisProcess of studying an existing system to determine how it works and how it meets user needs

Systems designProcess of developing a plan for an improved system, based upon the results of the systems analysis

January 23, 2003 8

Systems Analysis and Design: Why do it?

Impetus for change Internal force, e.g. improved productivity and

efficiency External force, e.g. meet regulatory

requirements or resolve customer issues Authority for change

Approval of higher management

January 23, 2003 9

Systems Analyst

Professional computer employee who performs analysis and design

Change agent Overcome reluctance of users to change

Typical career path Programmer Programmer / Analyst Systems Analyst

January 23, 2003 10

Systems Analyst: Functions

Coordination Schedules and system-related tasks Personnel

Manager Programmers Users Vendors of computer equipment Mail room employees Contractors

January 23, 2003 11

Systems Analyst: Functions

Communication Oral presentations Written documentation

Planning and design Plans and designs the new system Involved from beginning of project through final

implementation of the system

January 23, 2003 12

SDLC: Systems Development Life Cycle

Preliminary investigation Analysis Design Development Implementation

January 23, 2003 13

SDLC: Preliminary Investigation

Feasibility study / System survey Determine the problem Describe the problem Understand management decisions

Organizational chart Informal hierarchy

Produces rough plan and what to do

January 23, 2003 14


Problem Definition Nature of the problem

Separate problem from symptoms of problem

Scope of the projectEstablish boundaries..

Budget and schedule Objectives of the project

What user thinks system should do

January 23, 2003 15


ReportWhat you have found

Recommendations

Financially feasible

January 23, 2003 16


Resulting Management Decision Drop Fix a simple problem Authorize the analysis phase

January 23, 2003 17

SDLC: Analysis

Understand the existing system Gather data Analyze data

Establish system requirements

January 23, 2003 18

SDLC: Analysis – Data Gathering

Written documents Interviews

Structured Unstructured

Questionnaires Observation

Visits by appointment Participant observation

Sampling

January 23, 2003 19

SDLC: Analysis – Analyze Data

How the current system works Determine system requirements Basis for documentation Tools

Data flow diagram (DFD) Decision tables

January 23, 2003 20

SDLC: Analysis – Data Flow Diagram

January 23, 2003 21

SDLC: Analysis –Decision Tables

January 23, 2003 22

SDLC: Analysis – System Requirements

Detailed list of things the system must be able to do

Design is based upon system requirements Agreement upon requirements is needed

before proceeding

January 23, 2003 23

SDLC: Analysis – Report to Management

Summarize problems Describe requirements Cost analysis Recommendations for next step Obtain authorization to proceed

January 23, 2003 24

SDLC: Design

Planning the new system System Architecture Two Design Phases

Preliminary design (or external design) Detail design (or internal design)

January 23, 2003 25

SDLC: Preliminary Design

Major system aspects Centralized or distributed Online or batch PC-based? How will input be

captured? Necessary reports

January 23, 2003 26


Make or buy decision Packaged software

Meet at least 75% of requirements? Change business procedures for part or all of remainder? Customize for part of all of remainder?

Custom software Programmers write code

Outsourcing System is developed by external organization

January 23, 2003 27


Create an overall plan Offer alternatives that meet requirements Explain differences Evaluate costs

January 23, 2003 28


Build a prototype Limited working system of subset

Does not need true functionality Output looks like anticipated system output

Working model that can be modified and fine-tuned Uses high-level software tools – CASE Best for small-scale systems

January 23, 2003 29


CASE toolsComputer-Aided Software

Engineering Supports specific analysis and design tasks Integrated environment that supports the

entire systems development process

January 23, 2003 30


Presentation All alternatives Selected plan Prototype of the system Obtain authorization to proceed

January 23, 2003 31

SDLC: Detail Design

Parts of detail design phase Output requirements Input requirements Files and databases Systems processing Systems controls and backup

January 23, 2003 32

SDLC: Detail Design

Output requirements Medium Type of reports Contents

January 23, 2003 33

SDLC: Detail Design

January 23, 2003 34

SDLC: Detail Design

Input requirements Medium Content Input forms Validation Volume

January 23, 2003 35

SDLC: Detail Design

Files and Databases Organization Access Format of records Coordinate with database administrator

regarding external databases and updating

January 23, 2003 36

SDLC: Detail Design

Flowchart Symbols

January 23, 2003 37

SDLC: Detail Design

January 23, 2003 38

SDLC: Detail Design

Systems Controls and Backup Insure that input is processed correctly Prevent fraud and tampering System journals Backup of system files

January 23, 2003 39

SDLC: Detail Design

Report to Management Detailed design specifications report Presentation Obtain authorization to proceed

January 23, 2003 40

SDLC: Development

Doing the work to bring the new system into being

Scheduling

January 23, 2003 41

SDLC: Development

Programming Refine the design Detailed logic flowcharts and pseudocode

Testing Unit testing System testing Volume testing

January 23, 2003 42

SDLC: Implementation

Converting to the new system Training Equipment conversion File conversion System conversion Auditing Evaluation Maintenance

January 23, 2003 43

SDLC: Implementation – Training

Begin during testing User’s manual (Technical Writers) Hands-on Training consideration

Space Equipment Data User’s schedules

January 23, 2003 44

SDLC: Implementation – Conversion

Equipment Planning Installation of new equipment

File Manual to electronic Special programs to convert old format to new

January 23, 2003 45

SDLC: Implementation – Conversion

System Direct conversion Phased conversion Pilot conversion Parallel conversion

January 23, 2003 46

SDLC: Implementation –Auditing

Audit trail Trace output back to source

January 23, 2003 47

SDLC: Implementation – Evaluation

Working? Meets original requirements? Benefits Meets budget Improvements

January 23, 2003 48

SDLC: Implementation – Maintenance

Ongoing activity for life of system

January 23, 2003 49

welcome to cmpe003 personal computer concepts: hardware and software

Documents