WWW.DISSERTATION.XLIBX.INFO
FREE ELECTRONIC LIBRARY - Dissertations, online materials
 
<< HOME
CONTACTS



Pages:     | 1 |   ...   | 2 | 3 ||

«Abstract Large IT projects may not deliver what they promise. Often they are late. Often they are over budget. Often what is eventually delivered is ...»

-- [ Page 4 ] --

The changes to E represent revision and understanding of requirements (i.e. drift). A change may remove an old requirement or add a new one. The probability q of this happening to any individual requirement is very low. For example, in the experiments we will describe shortly, it was taken to 0.1%. At each simulation step, each requirement changes with probability q, so that on average (if we have 1000 potential requirements) one requirement will change with each step. Some of those changes will be to respecify (and consequently, unimplement) an expected requirement. Others will be to introduce a new requrement. This represents requirements drift.

16 Why Large IT Projects Fail - http://www.ecs.soton.ac.uk/˜ph/LargeIT.pdf

–  –  –

Figure 3: Two scenarios, showing requirements drifting over time. Percentages show achievement.

4.1 Experimental Results The results of a couple of experiments done with this model are shown in Figure 3 and Figure 4.

For both scenarios, the rate of drift q was set to 0.1%. For scenario A, the development rate p is 0.5% and for scenario B it is double that, at 1%.

The graph in Figure 4 showns that scenario A, with the lower development rate reaches the initial requirements after around 525 days, but at that time in reality it has only implemented 87% of the drifted requirements. In fact, this development never reaches the drifting requirements. If we accept 95% as our target, it takes considerably more than twice as long to get there.

Scenario B shows the same behaviour. With productivity doubled, it takes nearly 300 days to reach the original requirements and by day 600 we have still only implemented 95% of the drifted requirements.

4.2 How results support our conclusions The models of course are purely illustrative. They are themselves conjectures. We use them here to show the way that development proceeds and how the modest requirements drift makes an apparently acceptable plan actually return failure according to the criteria that we have established.

In scenario A, for example, the project may well have planned conservatively to deliver at 600 days anticipating the kind of diminishing returns that set in as the product grows. But at 600 days they have ony achieved 87% of what is then understood as the requirements. Anticipating drift, the project would have invested more at the outset and perhaps achieved 95% of requirements by day 600. The amount of additional investment would however be about double, as a comparison between scenarios A and B will support.

It is likely, in practice, of course that realisation that the target is not going to be achieved will be apparent some time before the due date and a correction will be made at that time. This will reduce the total cost somewhat, but it will not be less than if the initial investment had been adequate.

–  –  –

400 300 200 100

–  –  –

We claim that a recognition of requirements drift by all parties to the project, but in particular the engineers and their immediate managers will lead to more conservative decisions relating to the plans made for a given investment. Being aware that drift happens and is an inevitable consequence of the need for an organisation to learn, will lead to a project management and execution behaviour that constantly looks for drift. Attending to the requirements, for example by engaging relevant parties in analysis sessions in which the requirements are continuously revisited, will likely expose drift early enough that its effect (of elongating the schedule, increasing the cost or reducing the delivered quality) can at least be anticipated at an earlier stage.

The problem, of course, is believing that drift is so pernicious. It is, after all, just a lot of very small changes, each of which is of little consequence. But if the project team really believes that this is the underlying cause of failure, then they will be prepared to pay more attention to being pedantic about their understanding of requirements. There is no silver bullet here. It’s not that simply “involving the customer earlier” will solve the problem. The team have to believe that, even when they do this, the requirements will continue to drift. Indeed, giving too much control to the customer, will simply accelerate the drift.

These observations are just as true when we adopt an Open Systems approach [Krechmer 2005], using components that implement open standards and are to a large extent plug-and-play [Veryard 2000].

This approach may raise the level of complexity with which a project can cope and are normally essential to a modular approach, allowing subsystems developed independently to interoperate. But they do not solve the problem of understanding the requirements and absorbing the drift.

On the other hand, the Open Source movement, which builds on open standards, may have some answers. Here components evolve in the true sense of that word, and the systems they contribute to also evolve. The advantage of this as a development method is that there is no cost associated with production. Schedules still obey some laws of evolution [Henderson 1998] and defy infinite compression, but there is no doubt that quality components do appear from this process. It is difficult to imagine “planning” a system delivery based on the anticipated production of new components by the Open Source method, but it is increasingly common to rely on Open Source components that exist at the outset of a project. The diminishing returns that exacerbate the drift we have observed will not be so apparent in these circumstances, since we will not be paying anything for development.

18 Why Large IT Projects Fail - http://www.ecs.soton.ac.uk/˜ph/LargeIT.pdf

6 Conclusions

We have argued that, many of the reasons given for the failure of large IT projects is an inadequte respect for the project’s understanding of requirements. We have tried to show that requirements drift either underlies the main reasons given for failure, or contributes to them in a significant way.

We have shown, in a model, that the diminishing returns experienced in a large projects as its product gets bigger is exacerbated by drift to the extent that projects may never achieve the kind of quality that makes their product acceptable. And finally, while offering no silver bullet, we have suggested that a true belief in requirements drift among engineers and their managers may itself go a long way towards mitigating its effects.

–  –  –

[Axelrod 99] Axelrod, R and M. D. Cohen, Harnessing Complexity - Organisational Implications of a Scientific Frontier. Free Press, NY, 1999 [BCS 2004] British Computer Society, The Challenges of Complex IT Projects. The report of a working group from the Royal Academy of Engineering and the British Computer Society, British Computer Society, 2004 [Boehm 1981] Boehm, B, Software engineering economics.. Prentice-Hall, Englewood Cliffs, NJ, 1981 [Boehm 2000] Boehm, B et al, Software cost estimation with Cocomo II. Prentice-Hall, Englewood Cliffs, NJ, 2000 [Britton 2003] Britton, N. F, Essential Mathematical Biology. Springer-Verlag, London, 2003 [Brookes 1979] Brookes, F. P, The Mythical Man-month. Addison Wesley, 1979 [Cambridge 2001] Cambridge Reporter, CAPSA and its implementation. Cambridge Reporter, 2/11/01, http://www.admin.cam.ac.uk/reporter [Chapman 2002] Chapman, J, System Failure. DEMOS, 2002 [Chatters 1998] Chatters, B, P. Henderson and C. Rostron, SIMMER: Software and Systems Integration Modelling Metrics and Risks (Getting to Level 4). EuroSPI 98, Goteborg, November 1998 [Grey 1995] Grey, S, Practical Risk Assessment for Project Management. Wiley, 1995 [Hayes 2003] Hayes, B, On the Threshold. American Scientist, Vol.91, Jan 2003 [Henderson 1998] Henderson, P, Laws for Dynamic Systems. Proceedings of International Conference on Software Reuse (ICSR 98), IEEE Computer Society Press, 1998

–  –  –

[Humphrey 2004] Humphrey, W.S, Why Big Software Projects Fail: The 12 Key Questions. The Journal of Defense Software Engineering, 2004 [Intellect 2003] Intellect, IT Supplier - Code of Best Practice. http://www.intellectuk.org, 2003 [Kauffman 2000] Kauffman, S, Investigations. OUP, 2000 [Krechmer 2005] Krechmer, K, The Meaning of Open Standards. The International Journal of IT Standards and Standardization Research, Vol. 4 No. 1, 2005.

[Neumann 1995] Neumann, P, Computer Related Risks. Addison Wesley, 1995 [NAO 2006] National Audit Office, National Programme for IT in the NHS Report by the Comptroller and Auditor General, HC 1173, http://www.nao.org.uk, 2006

–  –  –

[Petroski 1992] Petroski, H, To Engineer is Human - The role of failure in successful design.

Vintage Books, 1992 [Sauer 2003] Sauer, C and C. Cuthbertson, The State of IT Project Management in the UK 2002Templeton College, Oxford, www.cw360ms.com/pmsurveyresults/surveyresults.pdf, 2003 [Veryard 2000] Veryard, R, The Component Based Business - Plug and Play. Springer Practitioner Series [Wolstenholme 1990] Wolstenholme, E, System Enquiry, A System Dynamic Approach. John Wiley & Sons, New York 1990

[Xia 2004] Xia, W and G. Lee Grasping the Complexity of IS Development Projects. Comm. ACM, Vol.47, No.5, 2004

Pages:     | 1 |   ...   | 2 | 3 ||


Similar works:

«Media Industries Journal 2.1 (2015), ISSN: 2373-9037 Hollywood Creative Accounting: The Success Rate of Major Motion Pictures Sergio Sparviero 1 Paris Lodron University of Salzburg s.sparviero [AT] gmail.com Abstract: Academic, trade, and popular publications commonly assert that 80 percent of motion pictures fail to make a net profit, suggesting also that the main players of the motion picture industry operate in highly volatile market conditions. More importantly, major film companies use...»

«“Playful, irreverent, and deadly serious, Black Flags and Windmills is... a moving testimony of love, solidarity, betrayal, and the collective struggle for the freedom that so many of us yearn for.” —David Naguib Pellow, author of Resisting Global Toxics: Transnational Movements for Environmental Justice “It is a brilliant, detailed, and humble book written with total frankness and at the same time a revolutionary poet’s passion. It makes the reader feel that we too, with our...»

«Translating and The Computer 36 Terminology Management Revisited Nizar Ghoula Jaques Guyot Gilles Falquet University of Geneva The Olanto Foundation University of Geneva and The Olanto and The Olanto Foundation Foundation ABSTRACT Large repositories publishing and sharing terminological, ontological and linguistic resources are available to support the development and use of translation. However, despite the availability of language resources within online repositories, some natural languages...»

«The Officers, Directors and Members of US SAILING are pleased to present the ARTHUR B. HANSON RESCUE MEDAL to the crew of WAR BABY FOR THE RESCUE AS FOLLOWS: MIRACLE AT SEA Midnight Rescue of Man Overboard in Rough Seas Copyright 1990 Francie Manning 26815 Basswood Avenue Rancho Palos Verdes, CA 90274 U.S.A. Reproduced with Permission June, 1990. The 27th Sailing of the Newport to Bermuda Yacht Race. I was aboard Warren Brown’s 61foot sloop War Baby (formerly Ted Turner’s Tenacious),...»

«The Effects of Silicone Contamination on Bond Performance of Various Bond Systems G. L. Anderson, S. D. Stanley, G. L. Young, R. A. Brown, K. B. Evans, and L. A. Wurth Huntsville Space Operations ATK Aerospace Systems 620 Discovery Drive, Building 2, Suite 200 Huntsville, AL 35806 e-mail: gregory.anderson@atk.com Tel.: (256) 428-5849 FAX: (256) 544-0857 Key Words: contamination sensitivity, silicone contamination, epoxy, pressure sensitive adhesive, vulcanizing agents, tensile adhesion, peel...»

«Miyazawa Kenji’s “Preface” and Other Poems Translated by Tomiyama Hidetoshi and Michael Pronko Preface The phenomenon called I Is one postulated, organic alternating-current-lamp Blue illumination (A complex of all transparent ghosts) Together with scenes and with everyone Busily, busily flickering Very surely to keep on lighting, One karmic alternating-current-lamp Blue illumination (Light persisting, its electric lamp lost) These, from twenty-two months’ Direction sensed to be past...»

«ALSO BY CATHERINE COULTER THE FBI THRILLERS Nemesis (2015) Power Play (2014) Bombshell (2013) Backfire (2012) Split Second (2011) Twice Dead: Riptide and Hemlock Bay (2011) Whiplash (2010) KnockOut (2009) TailSpin (2008) Double Jeopardy (2008): The Target and The Edge Double Take (2007) The Beginning (2005): The Cove and The Maze Point Blank (2005) Blowout (2004) Blindside (2003) Eleventh Hour (2002) Hemlock Bay (2001) Riptide (2000) The Edge (1999) The Target (1998) The Maze (1997)...»

«Software Assurance Countermeasures in Program Protection Planning MARCH 2014 Deputy Assistant Secretary of Defense for Systems Engineering and Department of Defense Chief Information Officer Washington, D.C. Deputy Assistant Secretary of Defense for Systems Engineering (DASD(SE)) and Department of Defense Chief Information Officer (DoD CIO). 2014. Software Assurance Countermeasures in Program Protection Planning. Washington, D.C.: DASD(SE) and DoD CIO.Office of Primary Responsibility: Deputy...»

«ATO PORTARIA Nº 350, DE 18 DE JUNHO DE 2010 Altera o Anexo VIII do Volume I – Procedimentos Contábeis Orçamentários – do Manual de Contabilidade Aplicada ao Setor Público, aprovado pela Portaria Conjunta SOF/STN nº 2, de 6 de Agosto de 2009. O SECRETÁRIO DO TESOURO NACIONAL DO MINISTÉRIO DA FAZENDA, no uso de suas atribuições legais e tendo em vista o disposto no art. 50, § 2º, da Lei Complementar nº 101, de 4 de maio de 2000, Lei de Responsabilidade Fiscal; e Considerando o...»

«FLESHING OUT SKULL & BONES INVESTIGATIONS INTO AMERICA'S MOST POWERFUL SECRET SOCIETY DEDICATED TO My Father AT ONE TIME, HE PEDDLED SKULL & BONES IN HIS FRONT JOB FOR THE CIA. LLOYD SIDNEY MILLEGAN OSS/G2/CIA August 18, 1918 — February 7, 1990 Picture taken in Indonesia 1951 iii FLESHING OUT SKULL & BONES INVESTIGATIONS INTO AMERICA'S MOST POWERFUL SECRET SOCIETY TABLE OF CONTENTS ACKNOWLEDGEMENTS PREFACE ARTICLES EVERYTHING YOU EVER WANTED TO ASK BUT WERE AFRAID TO KNOW. 1 THE SEPTEMBER...»

«CHAPTER 4. THE WESTERN POWER AND SMELTING AERIAL TRAM SYSTEM (24PA879) Clear and warm. Visited the mines, found most of the lodes covered with snow from 2 to 10 feet deep, while a few are clear of snow. Most of the party are already becoming discouraged, & think the snow will remain all summer. I think different.-A.B. Henderson, June 12th, 1873 from: “Journal of Various Prospecting Trips, Stampedes, and [etc.] During the years 1871 and 1872” 4-1 The Western Power and Smelting Company...»

«2016 Tomato Variety List The Henrys’ Plant Farm Indeterminate: Tomato varieties that should be staked, trellised, or caged for best results. Tomato varieties blossom and set tomatoes until plants are killed by a freeze.Determinate: Tomato varieties that are spacesaving or bush type in the garden. They may be grown with or without support. The tomatoes ripen within a concentrated time period. Consider some varieties of this type if you want a supply of ample amounts of tomatoes for...»





 
<<  HOME   |    CONTACTS
2016 www.dissertation.xlibx.info - Dissertations, online materials

Materials of this site are available for review, all rights belong to their respective owners.
If you do not agree with the fact that your material is placed on this site, please, email us, we will within 1-2 business days delete him.