1. “What do I do ?”, “How do I do it ?”, What do I do it with ?
Requirements Specification, Design Specification & System Specification
“What do I do ?”,
“How do I do it ?”,
What do I do it with ?

2. Learning Objectives: describe the contents of the:
requirements specification,
design specification,
system specification,
..... distinguishing between them.

3. Specifications

4. Requirements Specification
produced during analysis stage
i.e. after the investigation phase
by the Systems Analyst
contains client requirements
what the client would like the system to do
setting targets for the system (deliverables)
the requirement specification is a contract
between client & developer
success (& payment) will be determined by the contents

5. Requirements Specification
“what the client would like the system to do”
input needs
data entry screens (& data validation)
data to be stored
entities
processing requirements
searches
calculations
output needs
on-screen results required
reports required

6. Design Specification Documentation produced by the designer showing:
“How” the solution is to be implemented
the data dictionary
tables, fields, data formats, validation routines & error messages, relationships, ERD
sketches of input screen layouts
sketches of output layouts (eg reports)
house style: fonts, colours, sizes & styles to use
types of data entry to use (combo box, option buttons ...)
button actions and other processes
formulae & calculations required
flow charts

7. System Specification identifies minimum software and hardware required
in order for the system to run effectively.
Includes:
input devices required (keyboard, mouse, )
output devices required (monitor, printer, .....)
processing power required (type, cores & clock speed)
memory (RAM) required
amount of storage required (hard drive capacity)
security requirements (anti-virus, firewall ...)
operating system
applications software