'Why Is Testing Stage of Sdlc so Important?\r'

'Why is the interrogatory stage of bodys reading so important? November 2012 Introduction • Systems nurture Lifecycle • Types of SDLC • Stages of SDLC • • • • • • • • • • falls method turn exposeing Programme interrogation credence exam Limitations of Testing Case theme 1: University of Salford Case Study 2: Knight dandy Group Summary Conclusion References Systems Development Lifecycle • Systems Development Life Cycle (SDLC) is the process of developing cultivation carcasss through various stages from identifying initial requirements through analysis, design, examen, mplementation and maintenance. • galore(postnominal) different models hardly each 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 • O ne of the oldest, best known • analogue sequential set of phases • Review at closure of each phase before moving on to the next • Logical chain of events, e. g. programming cannot bring forth until stipulation perpetrated • m each a(prenominal) different versions • M either critics †does not work? La thinkte & Neill (2004) Dennis et al (2008) Stages of SDLCVary according to the methodological analysis used but usually some novelty of the waterfall method which has Galin (2004) served as a fair example for others. • Systems analysis †identify problems & establish requirements • Systems Design †stool design specifications • Programming †translate design specification into code • Testing • Conversion †plan conversion, drawstring users • Production & Maintenance †operate, evaluate and modify the body Laudon & Laudon (2006) Testing Why test? System should be teste d to look that it meets the requirements laid out at the start of the process. Develop a test plan • Involve users as well as developers • posture data and test system processes e. g. entering a new record, inserting incorrect data Laudon & Laudon (2006) Test aim Test Number Purpose of Test Test Data Expected issuance Actual Result 1 Test the well-groundedation incur on the â€Å"Date of Birth” field to ensure that valid dates of birth can be entered. 15/02/1988 trustworthy 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 competent from: Laudon & Laudon (2006) Testing 2 basic phases of interrogation: course 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 T esting 3 phases • unit testing †individual modules of the system are tested for any potential errors in the code. • integration testing †to finish the modules work together as expected • complete system testing †see how all the components allow work under various conditions Bocij et al (2006) acceptance Testing User betrothal Testing (UAT) by actual end users of the ystem to determine how well it meets their expectations and requirements. • of import testing †using simulated data • beta testing †using actual data †nett stage before implementation Bocij et al (2006) Acceptance Testing • Security testing †whether security policies film been implemented as intended • Recovery testing †how the system reacts when it has been forced to fail • Performance testing †in different environments • Stress testing †attempts to â€Å" pull” the system by not following guidelines. Lo oks at how the system performs under heavy 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 often given substandard brilliance and other stages overrun at the disbursement of testing • Cannot rule out unforeseen problems kick upstairs down the line BUT: Gives a good idea, identifies major errors Morris (2005), Bocij et al (2006) Case Study 1 †Careers process • New system to manage Careers Service meshings, industrial planthops and events • Alpha testing revealed few errors which were resolved • of import testing revealed significant issues re: student status, ducation details, appointment booking abilities • Issues were resolved and pilot system launched • Phased implementation. Testing continues… Case Study 2 †Knight metropolis Group • occupation US equities e lectronically (high frequence trading) • dormant(ip) software from a legacy system inadvertently reactivated • Multiplied stock trades by kelvin • 45 minute delay in shutdown down the system • Proper testing and â€Å" enamour market simulations” • Estimated $440M loss Detterman (2012), Ruhle, Harper and Mehta (2012) Summary • delimitate 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 rectify before implementation • Testing is a continuous process. There needs to be a carving off point before implementation but it can (and should) continue • Testing is critical because it is the alone way to determine whether the system operates to requirements and actually works! Laudon & Laudon (2006), Cervone (2007) Refe rences Cervone, H. F. (2007),”The system development life cycle and digital library development”, O CLC Systems & Services, Vol. 3 Iss: 4 pp. 348â€352 [online]. Available from: [Accessed 12 November 2012] Dennis, A. , Wixom, B. H. & Roth, R. M. (2008) Systems Analysis and Design, 4th Edn, Oxford: Wiley Detterman, E. (2012) â€Å" package Development Life Cycle (SDLC) Case Study †Result = $440m Loss. ” Solid Logic engine room. 12 tremendous 2012 [online]. Available from: [Accessed 11 November 2012] Galin, D. (2004) software Quality assumption: from theory to implementation. Harlow: Pearson Education Laplante, P. A. & Neill, C. J. (2004), â€Å"The Demise of the Waterfall precedent 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 Information Systems: Organization and Technology in the Networked En terprise, ninth ed. , New Jersey: Prentice-Hall Morris, S. , (2005) â€Å"Software Development Cycle”, Tessella Support Services plc, lendable 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]\r\n'