SOFTWARE DEVELOPMENT LIFE 
CYCLE 
BY – SHEFALI MISHRA 
MBA 1ST YEAR 
GBAMS, MZP 
S 
D 
L 
C
Unit - IV 
S 
D 
L 
C
SDLC OVERVIEW 
SDLC ( software 
development life cycle ) 
Is a process used by software 
industry to design , develop and ...
SOFTWARE DEVELOPMENT LIFE CYCLE 
Planning 
Development Defining 
Building Designing 
Testing 
SDLC 
S 
D 
L 
C
<Planning phase > 
Investigation 
• Determine if a new system is needed 
• Three primary task 
1- define the problem (by o...
<defining phase> 
What is system analysis ? 
• It determine the feasibility of a system , and how it will 
meet the requir...
(1) Feasibility study 
 Feasibility study is the process of determining whether a system is appropriate in the 
context o...
 Operational feasibility 
It is also known as ‘ behavioral feasibility’ , determine whether the proposed system will 
wor...
(2) Requirement analysis 
• It is the most crucial stage of the system analysis in which an 
analysis is done about who re...
(3) Structured analysis 
In analyzing the present system and liable future requirements of 
the proposed system , the anal...
Tools for system analysis and design 
In a system development process , one of the basic 
objective is to complete the dev...
DATA FLOW DIAGRAM 
NAME SYMBOLS FUNCTIONING 
ARROW 
CIRCLE 
ONE SIDE 
OPEN 
RECTANGLE 
SQUARE 
IT SHOWS DATA FLOW 
IT SHOW...
FLOW CHART 
NAME SYMBOL 
Terminal .. Start/Pause/ End 
Input/ output 
processing 
Flow line 
Decision making 
connector 
O...
SYMBOLS 
DATA FLOW DIAGRAM 
̪̪̪̪̪̪̪̪̪̪̪̪̪̪̪̪ 
Data flow diagram (DFD) graphically 
illustrates a system’s component 
proce...
SYMBOLS 
Data store consists of computer files 
database or any other form of data 
storage. The name of data store is 
wr...
Flow chart 
It is graphical design tool that depicts the physical media & 
sequence of processing steps used in an entire ...
Explanations 
Terminal It is used to indicate beginning 
( START ) , ending and Pause 
( HALT ) in the program logic 
flow...
Processing A processing symbol is used to 
represented arithmetic & data movement 
instruction . The logical process of 
m...
decision 
A decision symbol is used in a flow chart to 
indicate a point at which a decision has to be 
made . 
connector ...
PROTOTYPING 
Prototyping is an approach for developing information system 
quickly as compared to long – drawn process ado...
Identification of basic information 
developing the initial prototype 
Using the initial prototype 
Revising and enhancing...
EXPLAINATIONS- 
 Identification of basic requirement :- 
In this stage , the system designer works with users to understa...
Designing phase 
System design -: 
System design is the most crucial stage of system development process as 
the design de...
Physical design -: 
Physical design , also known as detailed design , translate the abstract 
logical design into specific...
Input design -: 
For generating outputs , matching inputs are require which requires input 
design . The objective of inpu...
Processing design -: 
It focuses on the design of software resources , that is the program 
needed by proposed information...
Documentation -: 
After completion of system analysis and design , documentation is 
required . Documentation describes ho...
Method of documentation 
Method 
• Conventional(cook 
book) 
• Play script 
• Caption 
• Matrix 
• Flow chart 
Condition f...
Testing phase 
System testing 
After system is completely designed , it is better to test its functionality before 
it is ...
1) Program testing -: 
A program represent the logical element of a system . For a 
program to run satisfactorily , it mus...
3) System testing :- 
It is designed to uncover the weakness not tracked in earlier tests . It tests 
the functioning of t...
System implementation / building phase 
It has different system , ranging from the conversion of basic application to 
a c...
 Hardware acquisition -: 
The type of hardware that is required for implementing a system is 
specified in system analysi...
 User training -: 
It is an important element of a system implementation because the new 
system operations are quite dif...
System maintenance / development phase 
After a system is implemented and is in operation , it requires 
maintenance on re...
THE END
Software development life cycle
Software development life cycle
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Software development life cycle

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Detail presentation about software development life cycle with enhanced overview .
by shefali mishra
MBA 1st sem
GBAMS

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Software development life cycle

  1. 1. SOFTWARE DEVELOPMENT LIFE CYCLE BY – SHEFALI MISHRA MBA 1ST YEAR GBAMS, MZP S D L C
  2. 2. Unit - IV S D L C
  3. 3. SDLC OVERVIEW SDLC ( software development life cycle ) Is a process used by software industry to design , develop and test high quality software . SDLC aims to produce a high quality software that meet or exceeds customer expectations , reaches completion within time and cost estimate . SDLC is a process followed for a software project, within a software organization . It consist of a detailed plan describing how to develop , maintain , replace and alter or enhance specific software . The life cycle defines a methodology for improving the quality of software and the overall development process. S D L C
  4. 4. SOFTWARE DEVELOPMENT LIFE CYCLE Planning Development Defining Building Designing Testing SDLC S D L C
  5. 5. <Planning phase > Investigation • Determine if a new system is needed • Three primary task 1- define the problem (by observation and interview determine what information is needed by whom , where and why) . 2- suggest alternative solutions. 3- prepare a short report P L A N N I N G P H A S E
  6. 6. <defining phase> What is system analysis ? • It determine the feasibility of a system , and how it will meet the requirements of the system users . • The major function of system analysis are defining requirements , gathering data , analyzing data , drawing up system specification , designing system and testing system . • System analysis involves the following aspects of system development . 1) Feasibility study 2) Requirement analysis 3) Structured analysis D E F I N I N G P H A S E
  7. 7. (1) Feasibility study  Feasibility study is the process of determining whether a system is appropriate in the context of organizational resources & constraints and meet user requirement.  The basic objective of the feasible study are to identify whether the proposed system is feasible and will be more appropriate than the existing system .  A feasibility study covers economic , technical , operational , and legal feasibility .  Economic feasibility It involves determination of whether the given system is economically viable . It is done through cost / benefit analysis of the system to identify whether the benefit are more than the cost .  Technical feasibility It analysis whether the proposed system is technically viable with the available hardware , software , and technical resources .
  8. 8.  Operational feasibility It is also known as ‘ behavioral feasibility’ , determine whether the proposed system will work effectively within the existing managerial & organization framework . For ex ; if the new system requires distributed database while the existing policy is to have centralized database.  Legal feasibility It tries to ensure whether the new system meets the requirements of various information technology regulation , such as privacy laws , computer crime laws , etc .
  9. 9. (2) Requirement analysis • It is the most crucial stage of the system analysis in which an analysis is done about who required which information in what form and when . • These four was very important aspects because a system is meant for it users and not for designer & operations • Requirement analysis defines the scope of the system and the function it is expected to perform . • If the system is not designed according to information required , it will to achieve its objective in spite of choosing the best system . • In this stage , the system development team might be more interested in an analyzing how users do the job & what information they need for doing the job . • For this purpose the team may use the variety of tools to identify the requirements procedures and forms used , on-site observation , interview questionnaires .
  10. 10. (3) Structured analysis In analyzing the present system and liable future requirements of the proposed system , the analyst collect a great deal of relatively unstructured data through manuals , interview , questionnaires & other sources ; structured analysis is undertaken which is set of techniques & graphical tools and allows the analysis to develop a new bind of system specification that are easily understandable to the users . It has the following features – a. structured analysis is graphic that presents a picture of what is being specified & is a conceptually easy to understand presentation of the application . b. the process used in structured analysis is partitioned so that a clear picture of progression from general to specific in the system flow emerges. c. Structured analysis is logical rather than physical . It specifies in a precise concise & highly readable manner the working of the system .
  11. 11. Tools for system analysis and design In a system development process , one of the basic objective is to complete the development process in as short as possible and to keep as much quality as possible . For this purpose , different development methodologies are used. A development methodology is a collection of methods , tools and techniques or whatever name is given to these over the period of time different tools have been used for system development , which are as follows :  Data flow diagram  Data flow chart
  12. 12. DATA FLOW DIAGRAM NAME SYMBOLS FUNCTIONING ARROW CIRCLE ONE SIDE OPEN RECTANGLE SQUARE IT SHOWS DATA FLOW IT SHOWS PROCESS IT SHOWS THE DATA STORE IT SHOWS THE EXTERNAL ENTITY
  13. 13. FLOW CHART NAME SYMBOL Terminal .. Start/Pause/ End Input/ output processing Flow line Decision making connector Oval Parallelogram Rectangle Flow line Diamond Circle
  14. 14. SYMBOLS DATA FLOW DIAGRAM ̪̪̪̪̪̪̪̪̪̪̪̪̪̪̪̪ Data flow diagram (DFD) graphically illustrates a system’s component processes and the flow of data between them . A DFD is constructed by using four types of symbols that show different entities & their relationship. ARROW Data flow shows the movement of data between process , data store and external entity . Data may be concerned with report , document , sales order or data from a computer file .it is represented by arrow. CIRCLE Process portrays the transformation of input data flow to output data flow . An example of process is transformation of an order into an invoice . Process is represented by circle in DFD
  15. 15. SYMBOLS Data store consists of computer files database or any other form of data storage. The name of data store is written inside the data store symbol. It is represented by an open rectangle in DFD. An external entity is either originator or receiver of information . External entities may be customer , suppliers , government agencies , or employee/ department within the organization outside the current system . It is represented by square in DFD . OPEN RECTANGLE SQUARE
  16. 16. Flow chart It is graphical design tool that depicts the physical media & sequence of processing steps used in an entire information system . These may be two types of flow chart .  System flow chart  Program flow chart Different types of symbol are used in flowchart .
  17. 17. Explanations Terminal It is used to indicate beginning ( START ) , ending and Pause ( HALT ) in the program logic flow . Input/ output It is used to denote any function of input/ output device in the program . If these is a program instruction to input data from any input device. It is indicated in the flow chart with an input/ output symbol
  18. 18. Processing A processing symbol is used to represented arithmetic & data movement instruction . The logical process of moving data from one location of the primary memory to another is also indicator by this symbol Flow line A flow line with arrow head is used to indicate the flow of operation , that is the sequence in which the instruction are to be executed .
  19. 19. decision A decision symbol is used in a flow chart to indicate a point at which a decision has to be made . connector If a flow chart become very large the flow line may start criss- crossing at many places that causes confusion and reduces understandability of flow chart similarly , a large flow chart cannot be put in single page and it has o be carried on the next page . In these cases , it is useful to utilize connector symbols .
  20. 20. PROTOTYPING Prototyping is an approach for developing information system quickly as compared to long – drawn process adopted in SDLC approach . It is the process of developing an experimental information system quickly & inexpensively for demonstration & evaluation so that end user can better determine information requirement . Prototype is a working version of an information system or part of the system but it is meant to be only preliminary model . once this become operational , it is further refined until it confirms precisely to user requirements .
  21. 21. Identification of basic information developing the initial prototype Using the initial prototype Revising and enhancing prototype If accepted Operation prototype Working prototype If not accepted If accepted If not accepted Process
  22. 22. EXPLAINATIONS-  Identification of basic requirement :- In this stage , the system designer works with users to understand their basic information requirement .  Developing the initial prototype :- Based on user requirement , the system developer develops the initial prototype quickly mostly by using fourth generation language .  Using the initial prototype :- After the initial prototype is ready , it is put to operation to determine what refinements are required users are encouraged to use the prototype as extensively a possible and are encouraged to give their suggestion for refinements .  Refining & enhancing the prototype :- If the initial prototype is not accepted ; that is it does not meet the users requirement , this is treated as working prototype requiring further refinement and enhancement . This process is repeated units the prototype becomes acceptable & usable as operational prototype .
  23. 23. Designing phase System design -: System design is the most crucial stage of system development process as the design determine the success or the failure of the system . It involves –  Reviewing the system’s information and functional requirements .  Developing a model of the new system including logical and physical specification of output , input , processing storage and procedures . Logical design -: Logical design also known as conceptual design , layout the components of the system and their relationship to each other as they appear to users , the major work in logical design is as follows –  Input / output specification  File specification [ file organization ]  Processing specification [ mode of data process ] D E S I G N I N G P H A S E
  24. 24. Physical design -: Physical design , also known as detailed design , translate the abstract logical design into specific technical design for new system . Output design -: Computer output refer to any information generated by a system whether printed or displayed . The main objective of a system is to generate information in form which user can use . Output may be presented to users either in printed form , or screen display form , for ex ; i. Tabular form ii. Graphic form iii. Printed form
  25. 25. Input design -: For generating outputs , matching inputs are require which requires input design . The objective of input design is to make data entry as easy , logical and free from error as possible . For capturing input data , different device can be used , such as keyboard , on-line entry without using keyboard and source data automation – scanner , voice input devices and sensors , when keyed input system which is most common is used , it requires form design . Coding , and data entry . Storage design -: In every information system , data storage is required for concurrent use as well as for future use , there can be two approaches for designing data storage system. o First , data can be stored in individuals files with one file for each application . o Second , a database can be developed which can be shared by different users as the need arises . Further , the database either centralized or distributed .
  26. 26. Processing design -: It focuses on the design of software resources , that is the program needed by proposed information system . Procedure design -: Procedure specify how the computer will function from data entry storage to output storage .
  27. 27. Documentation -: After completion of system analysis and design , documentation is required . Documentation describes how an information system work from both a technical & end –user stand point . It is a written record of different phases of system development and establishes designed performance . criteria for these phases , since documentation provides detailed procedure of how a system work ,such procedure should be prescribed for all types of personnel who come in contact with system these personnel are -: a) End users – [ detailed instruction for accessing the system ] b) Secondary users – [ instruction on to enter each kind of input ] c) Computer operating personnel – [ instruction for quality assurance ] d) Trainers - [ documentation for type of training ]
  28. 28. Method of documentation Method • Conventional(cook book) • Play script • Caption • Matrix • Flow chart Condition for use • Sequenced set of instruction or one job title or unit . • Sequenced set of instruction involving several job . • Un sequenced procedures • Two condition determine a procedure . • Supplement to post script or matrix.
  29. 29. Testing phase System testing After system is completely designed , it is better to test its functionality before it is installed without testing , two types of problem are likely to occur .  If the system has any error , this may appear much later , the time log between the cause and appearance of the problem may enhance correction time .  If the system errors may effect files & records in the system and a small problem may conceivably explode into a much larger problem . Steps in testing – For system testing , a testing plan showing sequence of testing , time schedule and personnel involved in testing should be prepared . After finalizing this plan , system testing steps should be followed which are as follows – 1) Program testing 2) String testing 3) System testing 4) Acceptance testing T E S T I N G P H A S E
  30. 30. 1) Program testing -: A program represent the logical element of a system . For a program to run satisfactorily , it must compile and test data correctly and tie up properly with other program of the system , program testing checks two types of errors –  Syntax error  Logical error  A syntax error is a program statement that violates one or more rules of the language in which it is written .  A logical error deals with incorrect data fields ,out of range item , and invalid combination . 2) String testing -: Various programs of a system are related to each other , even if all the program are working well independently . It is not that necessary they will work well jointly to ensure that all programs works well jointly .
  31. 31. 3) System testing :- It is designed to uncover the weakness not tracked in earlier tests . It tests the functioning of the system as a whole to determine whether the system is functioning the way it was conceived . It includes system failure &validation of entire system . 4) Acceptance testing :- It provides the final certification that the system is ready to be used in production setting . It is evaluated by users and reviewed by management , when all parties are satisfied the system is formally accepted for installation .
  32. 32. System implementation / building phase It has different system , ranging from the conversion of basic application to a complete replacement of the existing system . There are basically three types of replacement . o Implementation of computer system to replace a manual system when requires acquisition of computer hardware & software. o Implementation of new computer system to replace an existing one like mainframe to network of micro computer or independent computer to client/ server computing . o Implementation of a modified application to replace an existing one using the same computer . System implementation involves- • Hardware acquisition , • Software acquisition , • Installation , • Conversion , • User – training and • Post implementation evaluation . B U I L D I N G P H A S E
  33. 33.  Hardware acquisition -: The type of hardware that is required for implementing a system is specified in system analysis and design documentation after the specification are made available , the particular type of computer may be chosen or acquisition .  Software acquisition -: System analysis specifies the type of software that would be required to produce desired output to satisfy the user needs .  Installation -: During the process of acquiring hardware / software , installation work may processed , so that by the time , equipment arrive , the platform is ready for its installation , installation involves site preparation , equipments installation & equipment check out .  Conversion -: It is the process of changing over from the existing system to the new system . It may be from a manual system to computerized system .
  34. 34.  User training -: It is an important element of a system implementation because the new system operations are quite different as compared to old ones , from training point of view , users may be classified as computer operators and end users .  Computer operator training – training should be provided to computer operator , that is the person who will operate computer . In providing training to computer operation , it must be ensured that they are able to handle operation training should include such fundamental as how to run the computer on and use it and knowledge of what normal operations and use .  End user training – it may involve computer use particularly in the case of micro-computer network . End-user must be provided training about how to access data files , the form in which they will receive the output , and how to interpret the output . End user should be trained on data handling activities such as data editing , formulating enquiries and deleting records of data as well as formatting reports , documents , etc . Training tools –  User manual  Help screen  Job aids
  35. 35. System maintenance / development phase After a system is implemented and is in operation , it requires maintenance on regular basis . Generally , system maintenance is performed by theses reason – 1) To correct cross – Uncovering bugs in the programs or weakness in the design that were not detected during testing and correcting there weakness . 2) To keep system current – Over the time changes occur in the system’s environment that , require modification in the system design & software. 3) To improve the system – Continuous improvement in the system is required to meet user requirements . System maintenance may be undertaken either by in – house maintenance teamer the maintenance work can be assigned to vendor or other system maintenance agencies . D E V E L O P E M E N E T P H A S E
  36. 36. THE END

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