system study and design

1. SYSTEM STUDY
Informationsystemsprojects’originatefrom manyreasons: to achievegreater speed in
processing data, better accuracyand improved consistency, faster informationretrieval,
integrationof businessareas, reduced cost and better security. The sourcesalso vary
project proposalsoriginatewith departmentmanagers, senior executivesand systems
analysis.
Sometimesthereal originis anoutside source, such as a government agencywhich
stipulatessystemsrequirementstheorganizationmust meet. Whenthe request is made,
the first systems activity, thepreliminaryinvestigation, begins. Theactivityhasthree
parts: request clarification, feasibilitystudyand request approval
Existing System:
The existing system wasan automated system. But It wasfound to be inefficient in
meeting thegrowing demandsof population.
Drawbacks in the existing systems:
Disadvantageofthe existing system:

2. SYSTEM DESIGN
DATA FLOW DIAGRAMS:
Data flow diagrams(DFD) was first developed by LARRY CONSTANTINEasway
representing system requirementsina graphicalform; thislead to modular design. A
DFD describeswhat data flow (logical) rather thanhow they areprocessed, so it does
not depend on hardware, software, data structureor file organization. It is also known as
‘bubblechart’.
A Data Flow Diagramsisa structured analysisand designtool that canbe used for
flowcharting inplaceof, or in associationwith, information-oriented and process-
oriented systems flowcharts. A DFD is a network that describestheflow of data and the
processes that change, or transform, data throughout a system. Thisnetwork is
constructed byusing a set of symbols that do not imply a physicalimplementation. It
has the purposeof clarifying system requirementsand identifyingmajor
transformationsthat willbecomeprogramsinsystem design. So it is the starting point
of thedesign phasethat functionalitydecomposestherequirement specificationsdown
to the lowest level of detail.