Leon van der Berg & Christiaan Dotze Leon van der Berg & Christiaan Dotze

Documentation, Analysis and Design
Damelin Vaal
(Group Assignment)
Documentation, Analysis and Design
Damelin Vaal
(Group Assignment)

Index: Page | Content | 1 | Index (this page) | 2 | Question 1 | 3 | Question 1 (continued) | 4 | Question 1 (continued) | 5 | Question 1 (continued) | 6 | Question 1 (continued) | 7 | Question 1 (continued) | 8 | Question 1 (continued) | 9 | Question 1 (continued) | 10 | Question 1 (continued) & Question 2 | 11 | Question 2 (continued) | 12 | Question 2 (continued) | 13 | References | | |

Question 1
Explain the following phases of the SDLC: [50]

An overview of the SDLC:

a) Analysis * Systems analysis is a process of collecting factual data, understand the processes involved, identifying problems and recommending feasible suggestions for improving the system functioning. * Systems analysis involves studying the business processes, gathering operational data, understand the information flow, finding out bottlenecks and evolving solutions for overcoming the weaknesses of the system so as to achieve the organizational goals. * System Analysis also includes subdividing of complex process involving the entire system, identification of data store and manual processes. * During the analysis stage the project team determines the end-user requirements. Often this is done with the assistance of client focus groups. The project team documents all of the user requirements and gets a sign-off from the client and management to move forward with system design. * It is more of a thinking process and involves the creative skills of the System Analyst. It attempts to give birth to a new efficient system that satisfies the current needs of the user and has scope for future growth within the organizational constraints. The result of this process is a logical system design. * System analysis is a process that continues until a preferred and acceptable solution emerges * The major objectives of systems analysis are to find answers for each business process: * What is being done? * How is it being done? * Who is doing it? * When is he doing it? Why is it being done? * How can it be improved?

b) Design * The design phase is the “architectural” phase of system design. The flow of data processing is developed into charts. The project team determines the most logical design and structure for data flow and storage. For the user interface, the project team designs mock-up screen layouts that the developers use to write the code for the actual interface. * The design phase comes after a good understanding of customer’s requirements; this phase defines the elements of a system, the components, the security level, modules, architecture and the different interfaces and type of data that goes through the system. * Based on the user requirements and the detailed analysis of a new system, the new system must be designed. It is the most crucial phase in the development of a system * The logical system design arrived at as a result of system analysis and is converted into physical system design. In the design phase the SDLC process continues to move from the “what” questions of the analysis phase to the “how”. * The logical design produced during the analysis is turned into a physical design (a detailed description of what is needed to solve original problem). * Input, output, databases, forms, codification schemes and processing specifications are drawn up in detail. * The programming language and the hardware and software platform in which the new system will run are decided. * Data structure, control process, equipment source, workload and limitation of the system, Interface, documentation, training, procedures of using the system, taking backups and staffing requirement are also decided at this stage. * There are several tools and techniques used for describing the system design of the system. These tools and techniques are: * Flowchart * Data flow diagram (DFD) * Data dictionary * Structured English * Decision table and * Decision tree

c) Coding * The system design needs to be implemented to make it a workable system. This demands the coding of design into computer language, i.e., programming language. The real code is written here. * This is also called the programming phase in which the programmer converts the program specifications into computer instructions, which we refer to as programs. * During the construction phase (coding) developers execute the plans laid out in the design phase. The developers design the database, generate the code for the data flow process and design the actual user interface screens. During this phase, test data is prepared and processed as many times as necessary to refine the code. * It is an important stage where the defined procedures are transformed into control specifications by the help of a computer language. The programs coordinate the data movements and control the entire process in a system. * A well written code reduces the testing and maintenance effort. * It is generally felt that the programs must be modular in nature. This helps in fast development, maintenance and future changes, if required. * Programming tools like compilers, interpreters and language like c, c++, and java etc., are used for coding .with respect to the type of application. The right programming language should be chosen.

d) Testing * Before actually implementing the new system into operations, a test run of the system is done removing all the bugs, if any. * Testing is becoming more and more important to ensure customer’s satisfaction, and it requires no knowledge in coding, hardware configuration or design.

* Testing can be performed by real users, or by a team of specialized personnel, it can also be systematic and automated to ensure that the actual outcomes are compared and equal to the predicted and desired outcomes.

* It is an important phase of a successful system. After codifying the whole programs of the system, a test plan should be developed and run on a given set of test data. The output of the test run should match the expected results. Sometimes, system testing is considered as a part of implementation process. * Using the test data following test run are carried out: * Program test: When the programs have been coded and compiled and brought to working conditions, they must be individually tested with the prepared test data. All verification and validation be checked and any undesirable happening must be noted and debugged (error corrected). * System Test : After carrying out the program test for each of the programs of the system and errors removed, then system test is done. At this stage the test is done on actual data. The complete system is executed on the actual data. At each stage of the execution, the results or output of the system is analysed. During the result analysis, it may be found that the outputs are not matching the expected output of the system. In such case, the errors in the particular programs are identified and are fixed and further tested for the expected output. All independent modules be brought together and all the interfaces to be tested between multiple modules, the whole set of software is tested to establish that all modules work together correctly as an application or system or package.

* When it is ensured that the system is running error-free, the users are called with their own actual data so that the system could be shown running as per their requirements.

* During the test phase all aspects of the system are tested for functionality and performance. The system is tested for integration with other products as well as any previous versions with which it needs to communicate. Essentially, the key elements of the testing phase are to verify that the system contains all the end user requirements laid out in the analysis phase, that all the functions are accurately processing data, that the new system works with all other systems or prior systems, and that the new system meets the quality standards of the company and the customers.

e) Implementation and Maintenance

* After having the user acceptance of the new system developed, the implementation phase begins. Implementation is the stage of a project during which theory is turned into practice.

* The major steps involved in this phase are: * Acquisition and Installation of Hardware and Software B * Conversion * User Training * Documentation

* The hardware and the relevant software required for running the system must be made fully operational before implementation. The conversion is also one of the most critical and expensive activities in the system development life cycle. The data from the old system needs to be converted to operate in the new format of the new system. The database needs to be setup with security and recovery procedures fully defined * During this phase, all the programs of the system are loaded onto the user’s computer. After loading the system, training of the user starts. Main topics of such type of training are: * How to execute the package? * How to enter the data? * How to process the data (processing details)? * How to take out the reports?

* After the users are trained about the computerized system, working has to shift from manual to computerized working. The process is called Changeover. The following strategies are followed for changeover of the system. * Direct Changeover: This is the complete replacement of the old system by the new system. It is a risky approach and requires comprehensive system testing and training. * Parallel run : In parallel run both the systems, i.e., computerized and manual, are executed simultaneously for certain defined period. The same data is processed by both the systems. This strategy is less risky but more expensive because of the following facts: * Manual results can be compared with the results of the computerized system. The operational work is doubled. Failure of the computerised system at the early stage does not affect the working of the organization, because the manual system continues to work, as it used to do. * The documentation of the system is also one of the most important activities in the system development life cycle. This ensures the continuity of the system. Generally following two types of documentations are prepared for any system. * User Documentation: The user documentation is a complete description of the system from the user’s point of view detailing how to use or operate the system. It also includes the major error messages likely to be encountered by the user. * System Documentation: The system documentation contains the details of system design, programs, their coding, system flow, data dictionary, process description, etc. This helps to understand the system and permit changes to be made in the existing system to satisfy new user needs. * Maintenance is necessary to eliminate errors in the system during its working life and to tune the system to any variations in its working environments. It must meet the scope of any future enhancement, future functionality and any other added functional features to cope up with the latest future needs. It has been seen that there are always some errors found in the systems that must be noted and corrected.

* From time to time the system needs to be reviewed. The review of the system is done for: * Knowing the full capabilities of the system * Knowing the required changes or the additional requirements * Studying the performance.

Question 2 2.1) Draw an Activity diagram that shows the actions and events involved in withdrawing cash from an ATM machine. [25]

* A session is started when a customer inserts an ATM card into the card reader slot of the machine. * The ATM pulls the card into the machine and reads (validate) it. * The customer is asked to enter his/her PIN. * If a transaction is aborted due to too many invalid PIN entries, the session is aborted. If the reader cannot read the card due to improper insertion or a damaged stripe, the card is ejected, an error screen is displayed, and the session is aborted. * The customer is then allowed to perform one or more transactions. In this case the customer is prompted for the amount required. * The amount entered is verified to be available against the account balance. If true, the customer receives the requested cash amount. * When the customer is through performing transactions, the card is ejected from the machine and the session ends.

2.2) Draw a Class diagram for a sales order, use case (attributes and methods omitted for clarity) [25]

Reference

1. Bibliography: Sommerville, I. (2010) Software engineering. 9th edn. Boston: Addison-Wesley Educational Publishers. In-line Citation: (Sommerville, 2010) 2. Alwan, M. (2015) What is system development life cycle? Available at: https://airbrake.io/blog/insight/what-is-system-development-life-cycle (Accessed: 9 March 2016). 3. Bibliography: Phases of system development life cycle (no date) Available at: http://oer.nios.ac.in/wiki/index.php/Phases_of_System_Development_Life_Cycle (Accessed: 9 March 2016). In-line Citation: (Phases of system development life cycle, no date) 4. Bibliography: Morris, K. (2016) ‘Steps in the system development life cycle’, Small Business Chron, . In-line Citation: (Morris, 2016) 5. Bibliography: Inc, L.S. (2015) Activity diagram for ATM system (UML). Available at: https://www.lucidchart.com/pages/activity-diagram-for-ATM-system-UML (Accessed: 10 March 2016). In-line Citation: (Inc, 2015) 6. Bibliography: Corp, C.O. (2016) UML activity diagram - cash withdrawal from ATM. Available at: http://www.conceptdraw.com/examples/diagram-of-an-atm-cash-withdrawal (Accessed: 10 March 2016). In-line Citation: (Corp, 2016) 7. Bibliography: Class diagram for a sales order (no date) Available at: https://www.google.co.za/search?q=Class+diagram+for+a+sales+order&biw=1920&bih=955&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjR2cHo17jLAhXD3CwKHfbKDGUQsAQIGQ (Accessed: 11 March 2016). In-line Citation: (Class diagram for a sales order, no date)