Why Is Testing Stage of Sdlc so Important?

Why is the examination stage of systems development so important? November 2012 Introduction Systems Development Lifecycle Types of SDLC Stages of SDLC Waterfall method essaying curriculum examination credence Testing Limitations of Testing subject field Study 1 University of Salford campaign Study 2 Knight Capital Group Summary Conclusion References Systems Development Lifecycle Systems Development Life Cycle (SDLC) is the border of developing information systems through various stages from identifying initial requirements through analysis, design, test, mplementation and maintenance. Many different models but each(prenominal) generally consists of a series of defined steps or stages. Laudon & Laudon (2006) Types of SDLC Waterfall Fountain Spiral rapid prototyping Incremental Bocij et al (2006) Waterfall One of the oldest, best known Linear sequential set of phases check up on at end of each phase before moving on to the next system of logical com pass of events, e. g. programming stomachnot begin until specification completed Many different versions Many critics does not land? Laplante & Neill (2004) Dennis et al (2008) Stages of SDLCVary according to the methodology used but usually some variation of the waterfall method which has Galin (2004) served as a framework for others. Systems analysis identify problems & establish requirements Systems Design create design specifications Programming sympathise design specification into code Testing Conversion plan conversion, train users Production & Maintenance operate, tax and modify the system Laudon & Laudon (2006) Testing Why test? System should be tested to ensure that it meets the requirements set(p) come forth at the start of the process. Develop a test plan Involve users as headspring as developers Simulate data and test system processes e. g. entering a new record, inserting incorrect data Laudon & Laudon (2006) Test Plan Test Number Purpose of Test Test Data Expected outcome Actual Result 1 Test the validation rule on the Date of Birth playing field to ensure that valid dates of birth can be entered. 15/02/1988 Accepted Accepted 2 Test the validation rule on the Date of Birth field to ensure that a date in the future cannot be entered. 14/10/2013 Rejected Accepted Adapted from Laudon & Laudon (2006) Testing 2 radical phases of testing programme testing ensures that the programmes work as expected in controlled environment acceptance testing ensures users are able to use the system and that it operates as expected when in use. Laudon & Laudon (2006) Programme Testing 3 phases unit testing individual modules of the system are tested for any potential errors in the code. desegregation testing to check the modules work together as expected complete system testing suss out how all the components will work under various conditions Bocij et al (2006) Acceptance Testing User Acceptance Testing (UAT) by actual end users o f the ystem to determine how well it meets their expectations and requirements. alpha testing using bastard data beta testing using actual data final stage before slaying Bocij et al (2006) Acceptance Testing Security testing whether security policies have been implemented as think Recovery testing how the system reacts when it has been forced to fail Performance testing in different environments extend testing attempts to break the system by not following guidelines. Looks at how the system performs under threatening demand. Bocij et al (2006) Limitations of Testing Impossible to guarantee that once a system is tested it will work exactly as expected Too many factors to carry out exhaustive testing It is oftentimes given insufficient importance and other stages overrun at the expense of testing Cannot rule out unforeseen problems further down the line BUT Gives a good idea, identifies major errors Morris (2005), Bocij et al (2006) Case Study 1 Careers Service New system to manage Careers Service appointments, workshops and events Alpha testing revealed fewer errors which were resolved Beta testing revealed significant issues re student status, ducation details, appointment booking abilities Issues were resolved and buff system launched Phased implementation. Testing continues Case Study 2 Knight Capital Group Trading US equities electronically (high frequency trading) Dormant software from a legacy system inadvertently reactivated Multiplied agate line trades by 1000 45 minute delay in shutting down the system neat testing and appropriate market simulations Estimated $440M loss Detterman (2012), Ruhle, Harper and Mehta (2012) Summary Defined SDLC Types & Stages of SDLC Types of Testing Limitations of Testing Case studies demonstrate importance of thorough testing Conclusion Testing reveals any errors and incompatibilities Essential to ensure they can be corrected before implementation Testing is a continual process. There needs to be a cut off point before implementation but it can (and should) continue Testing is critical because it is the only way to determine whether the system operates to requirements and actually works Laudon & Laudon (2006), Cervone (2007) References Cervone, H. F. (2007),The system development vitality cycle and digital library development, O CLC Systems & Services, Vol. 3 Iss 4 pp. 348352 online. Available from Accessed 12 November 2012 Dennis, A. , Wixom, B. H. & Roth, R. M. (2008) Systems depth psychology and Design, 4th Edn, Oxford Wiley Detterman, E. (2012) Software Development Life Cycle (SDLC) Case Study Result = $440m Loss. Solid Logic Technology. 12 August 2012 online. Available from Accessed 11 November 2012 Galin, D. (2004) Software Quality Assurance from theory to implementation. Harlow Pearson Education Laplante, P. A. & Neill, C. J. (2004), The decease of the Waterfall Model Is Imminent and Other Urban Myths, ACM Queue, Vol 1, No. 10 onliine.Available from Accessed 12 November 2012 Laudon, K. C. and Laudon, J. P. (2006) Essentials of Management learning Systems Organization and Technology in the Networked Enterprise, ninth ed. , New Jersey Prentice-Hall Morris, S. , (2005) Software Development Cycle, Tessella survive Services plc, available at http//www. tessella. com/wp-content/uploads/2008/05/softwaredevelopmentcycle. p df accessed 12 November 2012 Ruhle, S. Harper, C. & Mehta, N. (2012) Knight Trading Loss Said to Be Linked to Dormant Software. Bloomberg. 14 August 2012. online Available from Accessed 01-11-2012