Different approaches to software design
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This document provides an overview of software engineering concepts related to software design. It discusses the definition and activities of software design, including preliminary and detailed design. It covers software design principles, considerations, and processes. It also describes various software design tools like data flow diagrams, structure charts, and entity-relationship models. Finally, it discusses object-oriented design, user interface design, data design, architectural design, interface design, and component-level design.
Different approaches to software design
- 1. E-Content on Software Engineering Lesson One : Definition and Activities Lesson Two : Software Design Principles Lesson Three : Software Design Consideration Lesson Four : Software Design Process Developed by Dr. Sandeep Kumar Nayak
- 2. The business process engineering hierarchy:
- 3. Software DesignSoftware Design: âąSoftware Design is a transformation of user requirement with reference to the SRS document into design documents which are appropriate for implementation using programming language.
- 4. Software DesignSoftware Design: âąTwo activities are performed in software design: âą Preliminary Design Identification various modules Relationship among modules Various interface designing Output is software architecture using notational diagram âą Detailed Design. Data structure designing Algorithms designing Output is the module specification document
- 5. Software DesignSoftware Design: âąIt is of two types: âą Function Oriented âąProblem can be viewed as a set of function. âąMost of the functions share global data. âą Object Oriented âąProblem can be viewed as a collection of objects âąData is hidden and can not be accessed by external functions.
- 6. Software DesignSoftware Design: Characteristics of good software design: âąCorrectness âąUnderstandability âąEfficiency âąMaintainability
- 7. Software Design Tool:Software Design Tool: Data Flow Diagram (DFD)Data Flow Diagram (DFD) :: âąTypes of DFD âą Logical DFD âą Physical DFD âąDFD Components
- 8. Software Design Tool: Data Flow Diagram (DFD) : âąLevels of DFD âą Level 0 Show entire system in one diagram with high level abstraction. âą Level 1 Show the basic modules of the system with data flow among them. âą Level 2 elaborate all the modules with data flow between, inside the modules and data store.
- 9. Software Design Tool: Structure Charts âąIt derived from the DFD and it more elaborative at lower level module
- 10. Software Design Tool: HIPO Diagram âąIt shows the modules hierarchy of system. âąIt shows the flow of data and control in a module.
- 11. Software Design Tool: Entity-Relationship Model âąIt shows the entities and their relationship.
- 12. âąModularization âą It follows divide and conquer rule. âą Software system divides into various independent module. âąAdvantage of modularization: âą Modules can be reused. âą Easy maintenance. âą Abstraction can be achieved easily. âą Concurrent processing of module can possible.
- 13. âąConcurrency âą Ability to execute more than one module in parallel to each other âą Identify modules which can be executed in parallel. âąDesign Verification âą Detection of mistake and missing. âą Structured verification approach for verification
- 14. âąSoftware Design Complexity âą Halstead's Complexity Measures âą Cyclomatic Complexity Measures âą Function Point
- 15. Object Oriented Design : Process Flow :
- 16. Object Oriented Design : UML diagrams : âąThis diagram captures the five view of a system. Userâs View Use case Diagram Structural View Class Diagram Object Diagram Behavioral View Sequence Diagram Collaboration Diagram State Chart Diagram Activity Diagram Implementation View Component Diagram Employment View Deployment Diagram
- 17. âą Class Diagram âą Object Diagram
- 19. âą State Chart Diagram âą Activity Diagram
- 21. âą Alternative approaches should be considered to avoid tunnel vision. âą Design should be mapped with the requirements. âą The gap between design and problem should be minimum. âą Uniformity should be exist in the design. âą Changes can be accommodate by the design whenever required.
- 22. âą To avoid inconsistency, ambiguity and omissions, design should be reviewed. âą Quality of design should be exist and maintain after development. âą Design is not a coding. âą For occurring any unexpected situation, design should be structured to degrade gently
- 23. âą Translating the analysis model into a software design
- 24. âą Translating the Object Oriented analysis model into a software design
- 25. âą Abstraction: procedural abstraction, data abstraction and Control abstraction âą Refinement: process of elaboration âą Modularity: Modular decomposability, Modular composability, Modular understandability, Modular continuity and Modular protection
- 26. âą Software Architecture; Structural properties, Extra-functional properties and Families of related systems âą Control Hierarchy: Levels of control (depth) , overall span of control (width), Fan-out, Fan-in, superordinate, subordinate, visibility and connectivity âą Structural Partitioning Horizontal partitioning and Vertical partitioning
- 27. âą Data Structure logical relationship among individual elements of data âą Software Procedure Details (data organization, structure, repetitive operation, sequence of events, and exact decision points) of processing of procured should be defined correctly. âą Information Hiding Non relevant information should not be accessible among the modules
- 28. âą functional independence Error isolation, Scope of reuse, Understandability
- 29. Cohesion: âąCoincidental cohesion: performs a set of tasks that relate to each other very loosely âąLogical cohesion: elements of the module perform similar operations âąTemporal cohesion: all the functions must be executed in the same time span âąProcedural cohesion: set of functions of the module are all part of a procedure
- 30. Cohesion: âąCommunicational cohesion: all functions of the module refer to or update the same data structure âąSequential cohesion: elements of a module form the parts of sequence âąFunctional cohesion: different elements of a module cooperate to achieve a single function
- 31. Coupling âąData coupling: two modules are communicated using parameters. âąStamp coupling: two module are communicated using composite data items âąControl coupling: execution of second module depend on the data of one module âąCommon coupling: share global data between two modules âąContent coupling: share code between two modules
- 33. âą Data Design Transformation of information model into data structures which are essential in the implementation. âą Architectural design Describes the design patterns, relationship between elements and the rules. âą Interface design Defines the communication between humans and the software. âą Component-level design Defines the procedural description of elements of the software architecture.
- 34. Data Design: âąData Modeling, âąData Structures, âąDatabases, âąData Warehouse
- 35. Architectural Design Patterns âąData-centered architectures
- 36. Architectural Design Patterns âąData-flow architectures
- 37. Architectural Design Patterns âąLayered architectures
- 38. USER INTERFACE DESIGN: Characteristics of good user interface design âąSpeed of learning âąSpeed of use âąSpeed of recall âąError prevention âąAttractiveness âąConsistency âąFeedback âąSupport for multiple skill levels âąError recovery (undo facility) âąUser guidance and on-line help
- 39. Types of User Interface Design: It can be designed into the following three categories: âą Command language based interfaces A command language-based interface is designed unique names to the different commands. âą Menu-based interfaces A menu-based interface is designed using menu selection through pointing device with least typing effort âą Direct manipulation interfaces Direct manipulation interface is designed in the form of visual models.
- 40. User Interface Design: Evaluation
- 41. User Interface Design: Process âąUser, task, and environment analysis and modeling âąInterface design âąInterface construction âąInterface validation
- 42. COMPONENT-LEVEL DESIGN : Flow Chart
- 43. Component-level design : Box diagram
- 44. Component-level design : Decision table
- 45. Component-level design :Resultant Decision table
- 46. Thank You