Summary of letures-8

Nature of good design
Design is process of describing,organizing and structuring system components at architectural design level and detailed design level
*Focussed on construction
*Simmilar to developping blueprints
Design components of new system are
1.Application architecture
2.user interfaces
3.system interfaces
4.database
5.network diagram
6.system control
The main outcome of design will become as diagrams and charts of proposed system

Summary of lectures 7

Finishing Analysis
This part is mainly done by he project manager with the support of developer team and priotize requirments on scope and level of automation.
1. This means the functions new system will support
2. Level of automation means how automated the selected functions will be.
Application developement enviorment
Computer hardware, systems software and networks.
Determine what alternatives are possible fordeveloping solution• Implementation alternatives include:– Building system in-house– Buying packaged or turnkey solution– Contracting with developer to build it (outsource)• Develop recommendations and present tomanagement to make funding decisions.

Summary of lecture - 6

Use Case modeling
What is use case modeling?
This is a graphical model that represents the users with system involvement
Relationships between usecase
Documents situation where one use case requires the services of a common
subroutine
• Another use case is developed for this common subroutine
• A common use case can be reused by multiple use cases
What is Activity diagram?
Diagram showing business process activities.
Ex - UML Diagram, usecase diagram and sequence diagram
SSD lifelines

Vertical line under object or actor:
– Shows passage of time
• If vertical line dashed:
– Creation and destruction of thing is not important for scenario
• Long narrow rectangles:
– Activation lifelines emphasize that object is active only during part of scenario
Domain model class diagram
This provides definition of system components and contains important class information for implementation as well as conceptual data model.
Object-oriented approach has complete set ofdiagrams that together document the user’sneed and define system requirements• Requirements specified using followingmodels:– Domain model class diagrams– Use case diagrams– Use case detailed model, either descriptive format oractivity diagram– System sequence diagrams (SSDs).

Summary of lectures 5

Week 5 - Tradditional or structured approach to Analysis
DFD and levels of abstraction
*these are the diagrams that provide multiple level of detail
*Higher level diagrams provide general view of system
*Low level diagrams peovide detail level of system
*Different views are known as level of abstraction

Context diagrams
This is a DFD that summarizes all the processing activity and shows system boundaries.
*this used OOA also

INFORMATION ENGINEERING MODELS
This mainly focuses on Enterprise size, data requirments and Strategic planning
This shares features with structured system developement

Mainly DFD's are easy to read and can show all the key features of system
Analyst may define processes as structured English process specification, decision table, decision tree, or process decomposition DFD
Models from IE may supplement DFDs– Process decomposition diagram (how processes onmultiple DFD levels are related)– Process dependency diagram (emphasizesinteraction with stored entities)– Location diagram (geographic where system used)– Activity-location matrix (which processes areimplemented at which locations)– Activity-data (or CRUD) matrix (where data used).
End of lecture