Waterfall Model Lifecycle Model Information Technology Essay

Waterfall Model Lifecycle Model Information Technology Essay Waterfall approach was first Process Model to be introduced and followed widely in Software Engineering to ensure success of the project. In The Waterfall approach, the whole process of software development is divided into separate process phases. The phases in Waterfall model are: Requirement Specifications phase, Software Design, Implementation and Testing Maintenance. All these phases are cascaded to each other so that second phase is started as and when define set of goals are achieved for first phase and it is signed off, so the name Waterfall Model. All the method and process undertaken in Waterfall Model are more visible. Waterfall Model lifecycle modelE:PROGECTpicture]water fall model.JPG Figure 1. : Waterfall Model lifecycle model The stages of The Waterfall Model are Problem definition In this section, you give a short, general description of the system To be analyzed. This should contain a very short description of the Organization or the company for which the analysis is to be done as Well the reasons and advantages why the computerization is needed. The environment of the analysis being done is to come out clearly in This section Requirement Analysis All possible requirements of the system to be developed are captured in this phase. Requirements are set of functionalities and constraints that the end-user (who will be using the system) expects from the system. The requirements are gathered from the end-user by consultation, these requirements are analyzed for their validity and the possibility of incorporating the requirements in the system to be development is also studied. Finally, a Requirement Specification document is created which serves the purpose of guideline for the next phase of the model. System Design Before a starting for actual coding, it is highly important to understand what we are going to create and what it should look like? The requirement specifications from first phase are studied in this phase and system design is prepared. System Design helps in specifying hardware and system requirements and also helps in defining overall system architecture. The system design specifications serve as input for the next phase of the model. Testing As specified above, the system is first divided in units which are developed and tested for their functionalities. These units are integrated into a complete system during Integration phase and tested to check if all modules/units coordinate between each other and the system as a whole behaves as per the specifications. After successfully testing the software, it is delivered to the customer Implementation On receiving system design documents, the work is divided in modules/units and actual coding is started. The system is first developed in small programs called units, which are integrated in the next phase. Each unit is developed and tested for its functionality; this is referred to as Unit Testing. Unit testing mainly verifies if the modules/units meet their specifications. Maintenance This phase of The Waterfall Model is practically never ending phase (Very long). Generally, problems with the system developed (which are not found during the development life cycle) come up after its practical use starts, so the issues related to the system are solved after deployment of the system. Not all the problems come in picture directly but they arise time to time and needs to be solve hence this process is referred as Maintenance. Advantages of the waterfall model The advantage of waterfall development is that it allows for departmentalization and managerial control. A schedule can be set with deadlines for each stage of development and a product can proceed through the development process like a car in a carwash, and theoretically, be delivered on time. Development moves from concept, through design, implementation, testing, installation, troubleshooting, and ends up at operation and maintenance. Each phase of development proceeds in strict order, without any overlapping or iterative steps. Needless to mention, it is a linear model and of lessons, linear models are the most simple to be implemented. The amount of resources required to implement this model is very minimal. One great advantage of the waterfall model is that documentation is produced at every step of the waterfall model development. This makes the understanding of the product designing procedure simpler. After every major stage of software coding, testing is done to test the correct running of the code. Prototyping Throw-away prototyping Throwaway or Rapid Prototyping refers to the creation of a model that will eventually be discarded rather than becoming part of the finally delivered software. After preliminary requirements gathering is accomplished, a simple working model of the system is constructed to visually show the users what their requirements may look like when they are implemented into a finished system. C:Documents and SettingsNIFRASDesktop1.JPG Figure 1.1: throw away proto typing Incremental Prototyping The final product is built as separate prototypes. At the end the separate prototypes are being merged in an overall design. C:Documents and SettingsNIFRASDesktop3.JPG Figure 1.2: Incremental Prototyping Evolutionary Prototyping Evolutionary Prototyping (also known as breadboard prototyping) is quite different from Throwaway Prototyping. The main goal when using Evolutionary Prototyping is to build a very robust prototype in a structured manner and constantly refine it. The reason for this is that the Evolutionary prototype, when built, forms the heart of the new system, and the improvements and further requirements will be builtC:Documents and SettingsNIFRASDesktop2.JPG Figure 1.3: Evolutionary Prototyping Advantages of prototyping Proto types make an ideal tool for defending discussing user interaction User can understand a prototype far easier than most of the standard base of communicating requirements in the form of the model Prototypes very quickly resolve misunderstanding between biasness manager analysis Disadvantages of proto typing Leads to implementing and then repairing way of building systems. Practically, this methodology may increase the complexity of the system as scope of the system may expand beyond original plans. The Spiral Model The spiral model, also known as the spiral lifecycle model, is a systems development method (SDM) used in information technology (IT). This model of development combines the features of the prototyping model and the waterfall model. The spiral model is intended for large, expensive, and complicated projects. The steps in the spiral model can be general as follows The new system requirements are define in as much detail as possible. This generally involves interviewing a number of users representing all the outside or internal users and other aspects of the existing method. A preliminary design is created for the new system. A first prototype of the new system is constructed from the preliminary design. This is usually a scaled-down system, and represents an approximation of the characteristics of the final product. A second prototype is evolved by a fourfold procedure: evaluating the first prototype in terms of its strengths, weaknesses, and risks; defining the requirements of the second prototype planning and designing the second prototype constructing and testing the second prototype. At the customers option, the entire plan can be aborted if the risk is deemed too great. Risk factors might involve development cost overruns, operating-cost miscalculation, or any other factor that could, in the customers judgment, result in a less-than-satisfactory final product. The existing prototype is evaluated in the same manner as was the previous prototype, and, if necessary, another prototype is developed from it according to the fourfold procedure outlined above. The preceding steps are iterated until the consumer is satisfy that the developed Prototype represents the finishing product desired. The final system is constructed, based on the refined prototype. Advantages of spiral model The spiral model is a realistic approach to the development of large-scale software products because the software evolves as the process progresses. In addition, the developer and the client better understand and react to risks at each evolutionary level. The model uses prototyping as a risk reduction mechanism and allows for the development of prototypes at any stage of the evolutionary development. It maintains a systematic stepwise approach, like the classic life cycle model, but incorporates it into an iterative framework that more reflect the real world. Disadvantages of spiral model      1. Highly customized limiting re-usability      2. Applied differently for each application      3. Risk of not meeting budget or schedule      4. Risk of not meeting budget or schedule C:Documents and SettingsAdministratorDesktopspiral model.png Figure 1.4: spiral model Rapid Application Development (RAD) Methodology what is RAD? RAD (rapid application development) is a concept that products can be developed faster and of higher quality through: Gathering requirements using workshops or focus groups Prototyping and early, reiterative user testing of designs The re-use of software components A rigidly paced schedule that defers design improvements to the next product version Less formality in reviews and other team communication Advantages of RAD Early visibility Greater flexibility Standardized look and feel Increased user involvement Buying may save money compared to building Disadvantages of RAD This method may not be useful for large, unique or highly complex projects This method cannot be a success if the team is not sufficiently motivated and nor is unable to work cohesively together. Success depends on the extremely high technical skills of the developers. C:Documents and SettingsNIFRASDesktopproto type.jpg Figure 1.4: RAD model Dynamic System Development Method Dynamic System Development Method is another approach to system development, which, as the name suggests, develops the system dynamically. This methodology is independent of tools, in that it can be used with both structured analysis and design approach or object-oriented approach. Advantages of DSD An importance on testing is so strong that at least one tester is expected to be on each project group Sets stakeholder expectations from the starts of the project that not all requirements will make it into the final deliverable Has specific approach to determining how important each requirements is to iteration Disadvantages of DSD Access to material is controlled by a consortium, and fees may be charged just to access the reference material Probably the most heavy weight project compared in this surveyC:Documents and SettingsAdministratorDesktopdynamic-system-development-method.jpg figure1.2.1: DSD method During the below given reasons I have chosen Waterfall Model for this project It is a linear sequential model It is very simple model to implement Easy to use It is the first model. It needs very few resources to implement Suitable for small projects Water fall model: This is very simple model. It moves like water fall from top to down of SDLC. The drawback of this model is ineffectiveness of verification and Validation activities. TASK 02 The water fall modelE:PROGECTpicture]water fall model.JPG The water fall stages Problem definition Requirement analysis System design Coding testing Implementation Maintenance 1. Problem definition In this section, you give a short, general description of the system to be analyzed. This should contain a very short description of the Organization or the company for which the analysis is to be done as Well the reasons and advantages why the computerization is needed. The environment of the analysis being done is to come out clearly in this section 2. Requirement Analysis All possible requirements of the system to be developed are captured in this phase. Requirements are set of functionalities and constraints that the end-user (who will be using the system) expects from the system. The requirements are gathered from the end-user by consultation, these requirements are analyzed for their validity and the possibility of incorporating the requirements in the system to be development is also studied. Finally, a Requirement Specification document is created which serves the purpose of guideline for the next phase of the model. 3. System Design Before a starting for actual coding, it is highly important to understand what we are going to create and what it should look like? The requirements specifications first phase are studied in this phase and system design is prepared. From System Design helps in specifying hardware and method requirements and also helps in defining overall system architecture. The system design specifications serve up as input for the next phase of the model. 4. Coding Testing As specified above, the system is first divided in units which are developed and tested for their functionalities. These units are integrated into a complete system during Integration phase and tested to check if all modules/units coordinate between each other and the system as a whole behaves as per the specifications. After successfully testing the software, it is delivered to the customer 5. Implementation On receiving system design documents, the work is divided in modules/units and actual coding is started. The system is first developed in small programs called units, which are integrated in the next phase. Each unit is developed and tested for its functionality; this is referred to as Unit Testing. Unit testing mainly verifies if the modules/units meet their specifications. 6. Maintenance This phase of (The Waterfall Model) is in effect never finish phase (Very long). Commonly, difficulty with the system developed (which are not found during the development life cycle) come awake later than its practical use start, so the issues related to the system are solved after deployment of the system. Not all the problems come in images directly but they arise time to time and needs to be solve hence this process is referred as Maintenance. 7. Specification Specification is the first step in the process. In this stage, companies find a problem they want to join and think of a viable result. They then write down the solution on paper and move on to the next stage in the waterfall standardization Testing includes verification and validation 1. Verification: Are we building the product right. 2. Validation: Are we building the right product 1. Validation Am I building the right product? Determining if the method complies with the requirements. And perform functions for which it is intended and meets and is performed at the finish of the project. Am I accessing the right data (in terms of the Data? Required to satisfy the requirement) High level activity Performs after a work product is produced against Established criteria ensuring that the product integrates correctly into the environment. Determination of correctness of the final software Product by a development project with respect to the user Needs and requirements. 2. Verification Am I building the product right? The review of interim work steps and interim Deliverables during a project to ensure them are Acceptable. To determine if the system is consistent, Adheres to standards, uses reliable techniques and prudent Practices, and performs the selected functions in the correct manner. Am I accessing the data right (in the right place; in? The right way) Low level activity Performed during development on key artifacts, like Walkthroughs, reviews and inspections, mentor feedback, Training, checklists and standards. My Opinion about This Task with Victoria Hospital The Victoria Hopital has some problems. The 1st problem is the victoria Hospital at presnt does not use Computer and not asystem to save data and details Appointment details, patient detail and payment detail. 2nd problem is cant V.H take a details in time of important.That problam is some time May be loss detail in physical fils so the V.H is face these problems becaus we can analysis requirements to the V.H those are need to V.H a good system to save details datas secent is the method should preparednes easy good to hendal to the operaters. 3rd problem is the implementations should have to a good system. 4th is give a good knowledge to operates.these implementations are want to V.H those are A Server Machine 5clients, 1GB Ram, or 512MB ,Laser Printer Dot matrix printer Bar code reader and the knowledge given by system supporters to Operater. Want to Operaters condect with system supporters and the system supporters must mainten the problems of system in time ofcoming problems. TASK 03 Data flow diagram Data flow diagrams can be use to provide an understandable representation of any business function. The system starts with an overall image of the business and continues by analyzing each of the functional areas of interest. This analysis can be carried out to precisely the level of detail required. The technique exploits a system called top-down expansion to conduct the analysis in a targeted way. C:Documents and SettingsAdministratorDesktopdfdg.JPG Figure 1.2.2: data flow diagram Process Processes show a transformation or manipulation of data flows within the system. The symbol used is a rectangular box which contains 3 descriptive elements: Firstly an identification number appears in the upper left hand corner. This is allocated arbitrarily at the top level and serves as a unique reference. Secondly, a location appears to the right of the identifier and describes where in the system the process takes place. This may, for example, be a department or a piece of hardware. Finally, a descriptive title is placed in the centre of the box. This should be a simple imperative sentence with a specific verb, for example maintain customer records or find driver. Data flow A data flow shows the flow of information from its source to its destination. A data flow is represented by a line, with arrowheads showing the direction of flow. Information always flows to or from a process and may be written, verbal or electronic. Each data flow may be referenced by the processes or data stores at its head and tail, or by a description of its contents. External entity An external entity is a source or destination of a data flow which is outside the area of study. Only those entities which originate or receive data are represented on a business process diagram. The symbol used is an oval containing a meaningful and unique identifier. Data storage A data store is a holding place for information within the system: It is represented by an open ended narrow rectangle. Data stores may be long-term files such as sales ledgers, or may be short-term accumulations: for example batches of documents that are waiting to be processed. Each data store should be given a reference followed by an arbitrary number. DFD context level diagram (0 level diagram) E:my project level df (1).jpg Figure 2.2.1: DFD context level diagram DFD 1st level E:PROGECTdrawing diagram dfdDrawing2.jpg Figure 2.3.1: DFD 1st level E:my project level df (5).jpg Figure 2.3.2 E:PROGECTdrawing diagram dfdDrawing4.jpg Figure 2.3.3 E:PROGECTdrawing diagram dfdDrawing5.jpg C:Documents and SettingsALLAHDesktop level df (11).jpg Entity relationship diagram C:Documents and SettingsAdministratorDesktopdfd4.JPG Entity A person, place, object events about which we need to compare store data are called as entities E.g. students, book, department Relational ship A relationship captures how two or more entities are related to one another. Relationships can be thought of as verbs linking two or more nouns. Relationships are represented as diamonds, connected by lines to each of the entities in the relationship. Relationship instance-link between entities (corresponds to primary key-foreign key equivalencies in related tables) Relationship type-category of relationshipà ¢Ã¢â€š ¬Ã‚ ¦link between entity types Attributes Attributes are the properties of entities relationship in other attributes is used to describe entities relationship in the ER diagram an entity has many attributes there for it needs to identifier. A key is attributes, group of attributes which we can use to identify an entity uniquely. Entity types E:my projectpicture]dd.jpg ERD diagram for Victoria hospital system D:tt.JPG Appointment to Patient One patient must have one appointment this is called one to one relationship and this is mandatory One appointment must have one patient this is called one to one relationship and this is mandatory Appointment to GP One GP have many appointments this is called one to many relationship and this is optional One appointment must have one GP this is called one to one relationship and this is mandatory Appointment to nurse One nurse have many appointments this is called one to many relationship and this is optional One appointment have many nurse this is called one to many relationship and this is optional Appointment to treatment One treatment have many appointments this is called one to many relationship and this is optional One appointment have many treatment this is called one to many relationship and this is optional Treatment to clinic One treatment have many clinic this is called one to many relationship and this is optional One clinic have many treatment this is called one to many relationship and this is optional E:my project1235.jpg TASK 4 Requirement specification NO Requirements BSO 1 BSO2 BSO3 BSO4 BSO5 1 Register patient Æ’Â ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ 2 Invoice the patient Æ’Â ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ 3 Inquiring handling â‚ ¬Ã‚  Ã¢â€š ¬Ã‚  Ã†â€™Ã‚ »Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚   â‚ ¬Ã‚  Ã†â€™Ã‚ » â‚ ¬Ã‚  Ã†â€™Ã‚ » â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ 4 Accept patient ordering Æ’Â ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ 5 printing debater report Æ’Â ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ 6 Medical laboratories Æ’Â » â‚ ¬Ã‚  Ã†â€™Ã‚ » â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ 7 Arrange the delivery Æ’Â ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ » â‚ ¬Ã‚  Ã†â€™Ã‚ » â‚ ¬Ã‚  Ã†â€™Ã‚ » â‚ ¬Ã‚  Ã†â€™Ã‚ » 8 Printing a patient report Æ’Â » â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ â‚ ¬Ã‚  Ã†â€™Ã‚ » â‚ ¬Ã‚  Ã†â€™Ã‚ ¼ Business system option (BSO) The set of Business System Options which is compiled so that a selection can be made. The selected Business System Option is a description of a chosen system development direction. The description documents the system boundary, inputs, outputs and the transformation taking place within the boundary. Essentially, the description is textual with supporting products such as Data Flow Diagrams, a Logical Data Structure and a Work Practice Model Technical system option (TSO) The set of Technical System Options which has been developed so that the system development direction can be chosen. Each option documents the functions to be incorporated and details implementation requirements. Each description is textual with some planning information. Functional elements are taken directly from the Requirements Specification Logical System Specification NO requirement TSO1 TSO2 TSO3 TSO4 TSO5 1 Visual basic 2007 Æ’Â ¼ Æ’Â ¼ Æ’Â ¼ Æ’Â » Æ’Â » 2 Windows 2003 Æ’Â ¼ Æ’Â » Æ’Â ¼ Æ’Â ¼ Æ’Â ¼ 3 Java J2SE Development Kit (JDK) 5.0 Æ’Â » Æ’Â » Æ’Â ¼ Æ’Â » Æ’Â ¼ 4 CCT camera Æ’Â » Æ’Â ¼ Æ’Â » Æ’Â » Æ’Â ¼ 5 A Server Machine Æ’Â ¼ Æ’Â ¼ Æ’Â » Æ’Â » Æ’Â ¼ 6 Firefox 9.02 latest version Æ’Â » Æ’Â » Æ’Â ¼ Æ’Â ¼ Æ’Â ¼ 7 5 clients,1GB Ram,80GB Æ’Â ¼ Æ’Â » Æ’Â » Æ’Â ¼ Æ’Â ¼ 8 SQL Server Æ’Â ¼ Æ’Â » Æ’Â » Æ’Â » Æ’Â ¼ 9 Windows 2007 Æ’Â » Æ’Â » Æ’Â ¼ 10 Laser Printer Æ’Â ¼ Æ’Â ¼ Æ’Â ¼ Æ’Â ¼ Æ’Â ¼ 11 Scanner Æ’Â ¼ Æ’Â » Æ’Â ¼ Æ’Â » Æ’Â ¼ 12 Credit Card reader Æ’Â ¼ Æ’Â ¼ Æ’Â ¼ Æ’Â ¼ Æ’Â ¼ 13 JDBC 3.0 compliant driver Æ’Â » Æ’Â ¼ Æ’Â ¼ Æ’Â » Æ’Â ¼ 14 IIS Server Æ’Â » Æ’Â » Æ’Â ¼ Æ’Â » Æ’Â ¼ 15 Dot matrix printer Æ’Â ¼ Æ’Â ¼ Æ’Â » Æ’Â » Æ’Â ¼ 16 Wi5 connection Æ’Â » Æ’Â » Æ’Â ¼ Æ’Â » Æ’Â ¼ 17 Win 2003 server Æ’Â ¼ Æ’Â ¼ Æ’Â ¼ Æ’Â ¼ Æ’Â ¼ 18 Barcode reader Æ’Â » Æ’Â ¼ Æ’Â » Æ’Â » Æ’Â » 19 Credit card Æ’Â ¼ Æ’Â » Æ’Â ¼ Æ’Â » Æ’Â ¼ . TASK 5 Fact-finding technique Interviews Questionnaires Observations Sampling Record-searching Fact-finding technique Fact-finding is a main activity in system investigation. In this chapter, the functioning of the method is to be understood by the system analyst to design the proposed system. Different methods are used for this and these are known as fact-finding techniques. The analyst needs to fully understand the current system. The analyst wants data about the requirements and demands of the project undertaken and the technique employed to gather this records are identified as fact-finding techniques. Various kinds of techniques are used and the most popular with them are interviews, questionnaires, record reviews, case tools and also the personal observations made by the analyst himself. Each of these techniques is additional dealt in next pages. Two people can go into the same area to gather facts and experience entirely different results. One spends weeks and gets incomplete and misleading data. The other is finished in a few hours and has complete and solid facts. This session outlines some of the things a person can do to achieve the latter. It covers: Interviews Interviewing is the one of the most common method in fact finding. It bring the analysis Into a direct contact with the users where he gets an opportunity to listen in to the opinion (advantage disadvantages) about the existing system also to identify the issues propose solutions the new system Interview is a very effective fact finding techniques. But the main problem is that it requires a lot of resources, especially time. So it is very important to plan the interview before hand the analysis is required to have considerable amount of skills Interview needs a start from the top level management to get permission also get an overview idea about the total system. Then the interview process can be move to which will provide more more specific details Interviews are not required to find out how exactly a system should work, but it needs to deter mine the needs of the users that we have to satisfy with a new system. The success of the interview depends upon the skills of the interviewer the preparation for the interview. Choose the person who is mostly appropriate for the interview Preparation for the interview Setting a proper date, and time ,venue the topic Correct sequence of questions These factors should include in an interview plan before conducing it. There are 3 types of questions usually asked in an interview Open questions Closed questions Probes questions Open question general questions that relates with the personal view on the subject Example-  Ã‚   what do you think of .?   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   What is your opinion of ?   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   How could . be improved. Advantages   Puts the interviewee at ease.   Permits extra questioning into area that was not anticipated during interview scheduling.   Provide detail. Disadvantages   interview may get off the track (i.e. the interviewer lose control of the interview) can be time-consuming, particularly if the interviewer is experience Closed question > question that is needed direct answer