Systems development

Dr. Al Bento University of Baltimore

Decision Model for Systems Development

Y'=a+bx

Development of TPS

the systems life cycle concept

systems analysis

systems design

implementation and maintenance

Systems Life Cycle concept

Analysis

Design

ImplementOperate

Maintain

Systems Analysis

Environment

Variance

I have aproblem!

user

analyst

information needs

information flows

symptons

Systems Design Specifications

Output specs (reports)

Input specs (input forms)

Data element dictionary

Systems diagrams

File / DB Design

Relationships of design specs

Systems diagrams

Data element dictionaryInput specs Output specs

File / DB design

1

3

4

2

Systems diagrams

Employees

YTD earningsTransaction

Paychecks W2 forms

EmployeesAccounting

Acct. reports

collect data

verify data

process payroll

process year-end

update ledger

distribute checks

time slips

Output specifications

Outputs are the system for the users

Key output questions who will receive the output what is the planned use when and how often is needed by what media (printed, visual,etc)

Output layout printer 80-124 columns, 50-60 lines display 80-? columns, 24-? lines components: headers, footers, fields drawing the layout

Output layout

1. use a word processor to prepare the layout2. number the columns as in example below 3. type the headers under these columns4. determine a format and length to the fields5. create an example for the field using Xs and 9s6. to show that it repeats copy one or two times the example

111111111112222222222333333333344444444445555555555666666666671234567890123456789012345678901234567890123456789012345678901234567890

New Employee and Termination Report

Dept Emp. No. Name Date hired Date Term. Cause99999 xxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx 99/99/99 99/99/99 xxx99999 xxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx 99/99/99 99/99/99 xxx

Input specifications

ENTER DO NOT ENTERidentification data constant datavariable data retrieved data computed data

S a l e s E n t r y Date: 06/15/99

Quantity Item Description Unit cost Total cost 18 46-1283 Sonic Circles 4.75 85.50

Item totals 85.50 Sales tax 5.99 Grand total 91.44Input layout: same as output layout

Systems implementation

Coding program specs test data documentation

System testing program testing system testing

Procedures and training

Installation parallel pilot