KUFA UNIVERSITY

KUFA UNIVERSITY

Department ofComputer Science

Fundamentals of Software Engineering

Presented ByPresented ByNeamah HassanNeamah Hassan

Presented ByPresented ByNeamah HassanNeamah Hassan

1-1- Requires before carrying out the development of the Requires before carrying out the development of the actual S/W actual S/W

2-2- at first work on prototype to develop at first work on prototype to develop

3-3- called as ( toy model ) called as ( toy model )

4-4- build with short cuts ( the short cuts might involve using build with short cuts ( the short cuts might involve using inefficient ,inaccurate , or dummy function ) inefficient ,inaccurate , or dummy function )

5-5- can be illustrate he I/P data format , msg , report and can be illustrate he I/P data format , msg , report and interactive dialogues to customer interactive dialogues to customer

6-6- especially useful for GUI as it become easy for the user to especially useful for GUI as it become easy for the user to form his opinion with working model rather than imaging form his opinion with working model rather than imaging a a hypothetical system hypothetical system

Prototype model

ContCont.….…

7-7- Its useful where the exact solutions to be adopted are Its useful where the exact solutions to be adopted are unclear to development teamunclear to development team

8-8- is submitted to customer and depending on feedback is submitted to customer and depending on feedback the requirement are refined the requirement are refined

ContCont.….…

RequirementsRequirementsGatheringGatheringRequirementsRequirementsGatheringGathering Quick DesignQuick Design

Refine RequirementsRefine Requirements

Build PrototypeBuild Prototype

Customer Evaluation of Prototype

Customer Evaluation of Prototype

DesignDesign

ImplementImplement

TestTest

MaintainMaintain

Customer

satisfied

Customer

satisfied

AdvAdv

1 - the actual code is thrown away but the 1 - the actual code is thrown away but the experience gained is useful to development the experience gained is useful to development the actual system actual system

2- associated redesign cost is reduced 2- associated redesign cost is reduced

3- useful when the exact solution are not clear to the 3- useful when the exact solution are not clear to the developers developers

shortcomingshortcoming

1- impossible to get it right at first chance1- impossible to get it right at first chance

2- more time is required 2- more time is required

3- additional cost3- additional cost

4- shows limited functional , low reliability , inefficient 4- shows limited functional , low reliability , inefficient performance performance

Evolutionary Evolutionary model

AB

C

A AB

Evolutionary Evolutionary model

1- referred as ( successive versions model and some 1- referred as ( successive versions model and some times as incremental model ) times as incremental model )

2- simple working is developed which subsequently 2- simple working is developed which subsequently undergoes many functionality improvement and undergoes many functionality improvement and additions until the desired system is realizedadditions until the desired system is realized

3- Some times called as design a little , build a little , 3- Some times called as design a little , build a little , test a little test a little

4- the S/W requirement is first broken down into 4- the S/W requirement is first broken down into several modules that can be incrementally several modules that can be incrementally constructed and delivered constructed and delivered

ContCont....

5- the development system first build a core modules 5- the development system first build a core modules and then the modules are incrementally developed and then the modules are incrementally developed

1- th1- th

1- the user get a chance to experiment with a partially 1- the user get a chance to experiment with a partially developed S/W before release of the complete developed S/W before release of the complete system .system .

2- testing of core modules is done thoroughly thus 2- testing of core modules is done thoroughly thus reducing chance of error reducing chance of error

4- waiting time at some time become easy 4- waiting time at some time become easy

advadv

Spiral model Spiral model

Determine ObjectivesDetermine Objectives

Identify & Resolve RisksIdentify & Resolve Risks

Develop Next Level of ProductDevelop Next Level of Product

Customer Evaluation of Prototype

Customer Evaluation of Prototype

Spiral model Spiral model

1- 1- the reason for its name is the diagramatic the reason for its name is the diagramatic representation of this model appears like a spiral with representation of this model appears like a spiral with many loopsmany loops

2-2- the exact number of loops is not fixed and vary from the exact number of loops is not fixed and vary from project to project project to project

3-3- every loop at this model called a phase of S/W process every loop at this model called a phase of S/W process

4-4- much more flexible compared with other model . much more flexible compared with other model .

5-5- Risk handling Risk handling

6-6- called as meta model bcz sometimes work as the reset called as meta model bcz sometimes work as the reset modelsmodels

Phases of the spiral model ..Phases of the spiral model ..

- First phase >> First phase >> some feature of the product are some feature of the product are identified based on the risk .identified based on the risk .

- Second phase >> Second phase >> the alternative solution are the alternative solution are evaluated to select the best possible solution evaluated to select the best possible solution

- Third phase >> Third phase >> consist of developing and verifying consist of developing and verifying the next level of the product the next level of the product

- Forth level >> Forth level >> concern reviewing the resultconcern reviewing the result

Adv Adv

1- less time is required bcz execute the step parallel 1- less time is required bcz execute the step parallel

2- risk analysis is done properly2- risk analysis is done properly

1- complex 1- complex

2- required knowledge staff2- required knowledge staff

- dis

Software project management Software project management

the main goal of S/W project management is to the main goal of S/W project management is to enable group of developers work efficiently towards enable group of developers work efficiently towards successful completion of the project successful completion of the project

1- estimation1- estimation

The project attributes have to be estimated The project attributes have to be estimated

A- costA- cost

How much the cost to develop S/WHow much the cost to develop S/W

Activities of project planning Activities of project planning

CONT…CONT…

B- duration B- duration

How long is it going to develop S/W How long is it going to develop S/W

C-Effort C-Effort

How much effort required to develop the product How much effort required to develop the product

2- scheduling 2- scheduling

After the estimation is made , the schedule for After the estimation is made , the schedule for manpower and other source have to developed manpower and other source have to developed

3- staffing 3- staffing

Staff organization and staffing plans have to be madeStaff organization and staffing plans have to be made

Metrics for project size estimation Metrics for project size estimation

The project size is a measure of the problem complexity The project size is a measure of the problem complexity in a terms of the effort and time required to develop the in a terms of the effort and time required to develop the product .product .

There are two metrics used to estimate size There are two metrics used to estimate size

A- lines of code ( LOC )A- lines of code ( LOC )

1-1-LOC LOC is simplest bcz the is simplest bcz the LOCLOC measure the size of project measure the size of project by counting the number of source instruction in the by counting the number of source instruction in the developed program developed program

Cont..Cont..

2- 2- more popular bcz it is simplest more popular bcz it is simplest

3- 3- while counting the number of source instruction the while counting the number of source instruction the lines of comments and header are ignores lines of comments and header are ignores

4-4- systematic guess is required systematic guess is required

Project mangers divided the problem in to modules and Project mangers divided the problem in to modules and each modules into sub modules until the size of different each modules into sub modules until the size of different leaf-level modules can be approximately estimated leaf-level modules can be approximately estimated

5-5- the the LOCLOC count at the end of project is very simple but count at the end of project is very simple but the accurate estimation of the accurate estimation of LOC LOC count at beginning of count at beginning of project is very difficult project is very difficult

Shortcoming Shortcoming

1-1- LOCLOC gives a numerical value of problem size that can gives a numerical value of problem size that can be vary with individual codingbe vary with individual coding

2-2- LOC LOC is measure the coding activity alone , but the good is measure the coding activity alone , but the good problem size should be measure the total effort needed , problem size should be measure the total effort needed , design , code , test , etcdesign , code , test , etc

3-3- LOCLOC is relates poorly with quality and efficiency of code is relates poorly with quality and efficiency of code

4-4- LOCLOC penalizes use higher – level language , code reuse penalizes use higher – level language , code reuse

B- FUNCTION POINT B- FUNCTION POINT

1-1- the the F/PF/P overcomes many of shortcomings of overcomes many of shortcomings of LOC LOC METRIC METRIC

22--F/P F/P has been slowly gaining popularity has been slowly gaining popularity

3-3- can be used to easily estimate the size can be used to easily estimate the size of S/Wof S/W directly directly from the problem specification from the problem specification

4-4-size of size of S/WS/W product is directly depend on the number product is directly depend on the number of functions or features it supported of functions or features it supported

5-5- a computation of the number of a computation of the number of I/PI/P AND AND O/PO/P data data values gives some indication of the number of function values gives some indication of the number of function supported by system supported by system

ShortcomingShortcoming

The major Shortcoming of The major Shortcoming of F/P F/P is that does not take in is that does not take in account the algorithms complexity of account the algorithms complexity of S/WS/W , the , the F/PF/P assumes that the effort required to design and develop assumes that the effort required to design and develop any two functionalities of the system are same . any two functionalities of the system are same .

Next lecture Next lecture Characterize of good software designCharacterize of good software design

Feature of software designFeature of software design

Approaches of software design Approaches of software design