Requirements1. Structured Analysis Method Structured system analysis and design (SSAD) Formal...
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Transcript of Requirements1. Structured Analysis Method Structured system analysis and design (SSAD) Formal...
![Page 1: Requirements1. Structured Analysis Method Structured system analysis and design (SSAD) Formal structured dev method Developed by UK Gov. in the 1980’s.](https://reader036.fdocuments.in/reader036/viewer/2022082620/5a4d1b1a7f8b9ab059993130/html5/thumbnails/1.jpg)
Requirements 1
![Page 2: Requirements1. Structured Analysis Method Structured system analysis and design (SSAD) Formal structured dev method Developed by UK Gov. in the 1980’s.](https://reader036.fdocuments.in/reader036/viewer/2022082620/5a4d1b1a7f8b9ab059993130/html5/thumbnails/2.jpg)
Structured Analysis MethodStructured system analysis and design
(SSAD)Formal structured dev methodDeveloped by UK Gov. in the 1980’sWe will focus only on analysis
Was used a lot when automating existing manual systems
Main stepsDraw a context diagramDraw DFD of the existing systemDraw DFD of the proposed system and identify the
man-machine boundaryRequirements 2
![Page 3: Requirements1. Structured Analysis Method Structured system analysis and design (SSAD) Formal structured dev method Developed by UK Gov. in the 1980’s.](https://reader036.fdocuments.in/reader036/viewer/2022082620/5a4d1b1a7f8b9ab059993130/html5/thumbnails/3.jpg)
Context DiagramThe context diagram - represent all external
entities that may interact with a system
Is a DFD with one transform (the system), with all inputs, outputs, sources, sinks for the system identified
The highest level view of a system
Requirements 3
SSAD Main steps1. Draw a context diagram2. Draw DFD of the existing system3. Draw DFD of the proposed system
and identify the man-machine boundary
![Page 4: Requirements1. Structured Analysis Method Structured system analysis and design (SSAD) Formal structured dev method Developed by UK Gov. in the 1980’s.](https://reader036.fdocuments.in/reader036/viewer/2022082620/5a4d1b1a7f8b9ab059993130/html5/thumbnails/4.jpg)
Example Context Diagram
Requirements 4
![Page 5: Requirements1. Structured Analysis Method Structured system analysis and design (SSAD) Formal structured dev method Developed by UK Gov. in the 1980’s.](https://reader036.fdocuments.in/reader036/viewer/2022082620/5a4d1b1a7f8b9ab059993130/html5/thumbnails/5.jpg)
DFD of the current systemThe current system is modeled as-is as a
DFD to understand the workingThe context diagram is refined Each bubble represents a logical
transformation of some dataLeveled DFD may be usedGenerally obtained after understanding
and interaction with usersValidate the DFD by walking through with
users
Requirements 5
SSAD Main steps1. Draw a context diagram2. Draw DFD of the existing system3. Draw DFD of the proposed system
and identify the man-machine boundary
![Page 6: Requirements1. Structured Analysis Method Structured system analysis and design (SSAD) Formal structured dev method Developed by UK Gov. in the 1980’s.](https://reader036.fdocuments.in/reader036/viewer/2022082620/5a4d1b1a7f8b9ab059993130/html5/thumbnails/6.jpg)
Modeling the Proposed SystemNo general rules for drawing the DFD of
the future systemUse existing system understandingDFD should model the entire proposed
system - process may be automated or manual validate with the user
Then establish man-machine boundarywhat processes will be automated and which
remains manualShow clearly interaction between
automated and manual processesRequirements 6
SSAD Main steps1. Draw a context diagram2. Draw DFD of the existing system3. Draw DFD of the proposed
![Page 7: Requirements1. Structured Analysis Method Structured system analysis and design (SSAD) Formal structured dev method Developed by UK Gov. in the 1980’s.](https://reader036.fdocuments.in/reader036/viewer/2022082620/5a4d1b1a7f8b9ab059993130/html5/thumbnails/7.jpg)
Example – context diagram
Requirements 7
![Page 8: Requirements1. Structured Analysis Method Structured system analysis and design (SSAD) Formal structured dev method Developed by UK Gov. in the 1980’s.](https://reader036.fdocuments.in/reader036/viewer/2022082620/5a4d1b1a7f8b9ab059993130/html5/thumbnails/8.jpg)
Example – DFD of existing sys
Requirements 8
![Page 9: Requirements1. Structured Analysis Method Structured system analysis and design (SSAD) Formal structured dev method Developed by UK Gov. in the 1980’s.](https://reader036.fdocuments.in/reader036/viewer/2022082620/5a4d1b1a7f8b9ab059993130/html5/thumbnails/9.jpg)
Example – DFD of proposed system
Requirements 9