Systems development Dr. Al Bento University of Baltimore.
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Transcript of Systems development Dr. Al Bento University of Baltimore.
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