Let Trust YourEstimates                 Volodymyr Voytyshyn                         02/19/2012
Have you ever estimateddevelopment tasks before startwork on them?How accurate were your estimates?What did you do when yo...
The Goal              How make  estimate of software project efforts               BETTER?
Main Points Why Good Estimate is Important? Some Anti-Patterns in Projects Estimation Estimation Approaches Overview PERT ...
WHY GOOD ESTIMATEIS IMPORTANT?
What is successful software project? All main requirements were implemented No time overhead No budget overhead No overtimes
Software Project Statistics                             CHAOS Summary 2009                 24%                            ...
What is the main problem?
When do we need estimates? Preparation of proposal for a new project Project planning Managing changes Managing risks Etc…
Why estimate is important?    Bad               Unsuccessful  Estimate              Project
Underestimation Consequences Demotivation Low Quality                Increase Growth of Costs                Etc…
SOME ANTI-PATTERNSIN PROJECTS ESTIMATION
Anti-Pattern #1  Estimate something when anybody do not  know what is this
Anti-Pattern #2 Talk “Yes” when you actually think “No”
Anti-Pattern #3 Forcible reducing of estimate
Anti-Pattern #4 Excessive optimism
Anti-Pattern #5 Make hasty estimates
Anti-Pattern #6 Software project includes only coding
Anti-Pattern #7 Not consider risks
ESTIMATION APPROACHESOVERVIEW
What is an estimate? Estimate is a probability value                      What is the confidence range?                   ...
Estimation Approaches                   Your own experience in similar                   projects                   Expert...
PERT PERT - Program / Project Evaluation and Review Technique The technique was designed at 1958 during project on the cre...
PERT: Calculations
PERT: Calculations
PERT: Calculations
Functional Point Analysis Was designed by Alan Albrecht and first published at 1979 Input data: logical model and requirem...
COCOMOCOCOMO – constructive cost modelWas designed by Barry Bouem and first publishedat 1981Input data: KLOC – thousands o...
PERT IN ACTION
Task Automated ordering system for company which specializing on wholesale trade Customer should be able to create an orde...
Estimation
Result
ConclusionA. Underestimate has very negative impact on   projectB. Software project estimation is not a guessingC. We can ...
Ask your question…
Information Sources Software Project Management Lectures http://www.arkhipenkov.ru 10 Deadly Sins of Software Estimation h...
Contacts                                   Volodymyr Voytyshyn                                   5 Knyahyni Olhy Str., Riv...
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Let trust our estimates

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Let trust our estimates

  1. 1. Let Trust YourEstimates Volodymyr Voytyshyn 02/19/2012
  2. 2. Have you ever estimateddevelopment tasks before startwork on them?How accurate were your estimates?What did you do when youunderestimated or overestimatedthe task?Have you ever estimated wholeproject before its start?
  3. 3. The Goal How make estimate of software project efforts BETTER?
  4. 4. Main Points Why Good Estimate is Important? Some Anti-Patterns in Projects Estimation Estimation Approaches Overview PERT in Action
  5. 5. WHY GOOD ESTIMATEIS IMPORTANT?
  6. 6. What is successful software project? All main requirements were implemented No time overhead No budget overhead No overtimes
  7. 7. Software Project Statistics CHAOS Summary 2009 24% 32% Failed Challenged Successed 44%http://www.standishgroup.com/newsroom/chaos_2009.php
  8. 8. What is the main problem?
  9. 9. When do we need estimates? Preparation of proposal for a new project Project planning Managing changes Managing risks Etc…
  10. 10. Why estimate is important? Bad Unsuccessful Estimate Project
  11. 11. Underestimation Consequences Demotivation Low Quality Increase Growth of Costs Etc…
  12. 12. SOME ANTI-PATTERNSIN PROJECTS ESTIMATION
  13. 13. Anti-Pattern #1 Estimate something when anybody do not know what is this
  14. 14. Anti-Pattern #2 Talk “Yes” when you actually think “No”
  15. 15. Anti-Pattern #3 Forcible reducing of estimate
  16. 16. Anti-Pattern #4 Excessive optimism
  17. 17. Anti-Pattern #5 Make hasty estimates
  18. 18. Anti-Pattern #6 Software project includes only coding
  19. 19. Anti-Pattern #7 Not consider risks
  20. 20. ESTIMATION APPROACHESOVERVIEW
  21. 21. What is an estimate? Estimate is a probability value What is the confidence range? What is the probability that we’ll exceed the estimate?
  22. 22. Estimation Approaches Your own experience in similar projects Expert’s estimation: – PERT, Program / Project Evaluation and Review Technique General techniques based on industry experience: – FPA, Functional Point Analysis – COCOMO, Constructive Cost Model
  23. 23. PERT PERT - Program / Project Evaluation and Review Technique The technique was designed at 1958 during project on the creation of missiles "Polaris" Input data: hierarchical structure of project tasks Output data: probabilistic estimation of efforts
  24. 24. PERT: Calculations
  25. 25. PERT: Calculations
  26. 26. PERT: Calculations
  27. 27. Functional Point Analysis Was designed by Alan Albrecht and first published at 1979 Input data: logical model and requirements for software project Output data: functional points Main benefit: unified and platform independent approach for estimation all projects in company
  28. 28. COCOMOCOCOMO – constructive cost modelWas designed by Barry Bouem and first publishedat 1981Input data: KLOC – thousands of logical codelinesOutput data: effort estimate in man-month
  29. 29. PERT IN ACTION
  30. 30. Task Automated ordering system for company which specializing on wholesale trade Customer should be able to create an order Manager should be able process an order Email notification for all steps of order workflow 1C synchronization
  31. 31. Estimation
  32. 32. Result
  33. 33. ConclusionA. Underestimate has very negative impact on projectB. Software project estimation is not a guessingC. We can use and combine several estimation approaches: – Experience on similar projects – PERT – FPA – COCOMO
  34. 34. Ask your question…
  35. 35. Information Sources Software Project Management Lectures http://www.arkhipenkov.ru 10 Deadly Sins of Software Estimation http://construx.com/Page.aspx?cid=2929 Software Estimation: Demystifying the Black Art http://www.microsoft.com/learning/en/us/book.a spx?ID=2425&locale=en-us
  36. 36. Contacts Volodymyr Voytyshyn 5 Knyahyni Olhy Str., Rivne 33000, Ukraine Tel: +38(066) 41 83 509 E-mail: vvoit@softserveinc.com voytyshyn@gmail.com Skype: voytyshin Thank You!Copyright © 2011 SoftServe, Inc.

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