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Software Project
Estimation
Theory and Reality
Andriy Tatchyn
General Manager at LaSoft
Table of content
• Introduction to estimation and estimation issues
• A theory of estimation
• Case Studies and real world...
Failure Record
• Every year only United States spend nearly $250 billion on IT
applications. Each year approximately 175, ...
“Bridges are normally built on-
time, on- budget, and do not fall
down. On the other hand,
software never comes in on-time...
Results
Source: Software Estimation: Demystifying the Black Art by Steve McConnell
Barry W. Boehm (born 1935) is an
American software engineer,
Distinguished Professor of
Computer Science, Industrial and
S...
• http://csse.usc.edu/tools/COCOMOII.php
CoComo II
adjustment factors
In many cases you will not be able to use
Cocomo 2 because:
- The project size is not clear, ...
Hello my friend,
how long will it take
to deliver the
project?
This is how Business works and thinks:
Source: Software Estimation: Demystifying the Black Art by Steve McConnell
Distinguish between
estimates, targets, and
commitments.
Source: Software Estimation: Demystifying the Black Art by Steve McConnell
This is how real world looks like:
Source: Software Estimation: Demystifying the Black Art by Steve McConnell
There is no single
point estimation
• While project in a progress it
develops information that support
more accurate estim...
The Cone of Uncertainty
Source: Software Estimation: Demystifying the Black Art by Steve McConnell
Recognize a mismatch
between a project’s business
target and a project’s estimate
for what it is: valuable risk
informatio...
Case Studies
How I estimate software projects
• Collect as much information about the project as possible. You will need at
least sever...
• Budget expectations
• Schedule expectations
• Functional Requirements
• Non-functional requirements
Collect
• Mockups
• ...
Define your customer
needs, schedule and
budget early. Share your
thoughts openly.
(Raboph Case Study)
Wristo Project,
Historical data
implementation
Number of pages: 6
Effort: 435 hours
Effort per page: 72,5 hours
Cost calcu...
Example of Bottom Up estimation
Remember about Indians,
Chinese and the rest of the
world
(Manmeet story)
Thank You!
Questions and ideas are welcome!
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Андрій Татчин "Software Project Estimation: Theory and Reality"

  1. 1. Software Project Estimation Theory and Reality Andriy Tatchyn General Manager at LaSoft
  2. 2. Table of content • Introduction to estimation and estimation issues • A theory of estimation • Case Studies and real world examples
  3. 3. Failure Record • Every year only United States spend nearly $250 billion on IT applications. Each year approximately 175, 000 projects are built. Many of those are fail. • The Standish Group research shows a staggering 31.1% of projects that were cancelled before they ever got completed. Further results indicate 52.7% of projects will cost 189% of their original estimates. • The cost of these failures and overruns are just the tip of the proverbial iceberg. The lost opportunity costs are not measurable, but could easily be in the trillions of dollars. Source: The Standish Group Report 2014
  4. 4. “Bridges are normally built on- time, on- budget, and do not fall down. On the other hand, software never comes in on-time or on-budget. In addition, it always breaks down.” Alfred Spector, President of Transarc Corporation
  5. 5. Results Source: Software Estimation: Demystifying the Black Art by Steve McConnell
  6. 6. Barry W. Boehm (born 1935) is an American software engineer, Distinguished Professor of Computer Science, Industrial and Systems Engineering; the TRW Professor of Software Engineering; and Founding Director of the Center for Systems and Software Engineering at the University of Southern California. Source: Wikipedia
  7. 7. • http://csse.usc.edu/tools/COCOMOII.php
  8. 8. CoComo II adjustment factors In many cases you will not be able to use Cocomo 2 because: - The project size is not clear, and you have no idea how many lines of code (LOC/SLOC) the project will have. - In most cases today we use several programming languages and frameworks to develop software. So Locs becoming less universal. - In most cases, it is recommended to use your organizations' historical data and take into account described Cocomo 2 adjustment factors. Source: Software Estimation: Demystifying the Black Art by Steve McConnell
  9. 9. Hello my friend, how long will it take to deliver the project?
  10. 10. This is how Business works and thinks: Source: Software Estimation: Demystifying the Black Art by Steve McConnell
  11. 11. Distinguish between estimates, targets, and commitments.
  12. 12. Source: Software Estimation: Demystifying the Black Art by Steve McConnell
  13. 13. This is how real world looks like: Source: Software Estimation: Demystifying the Black Art by Steve McConnell
  14. 14. There is no single point estimation • While project in a progress it develops information that support more accurate estimation. We have better understanding of requirements, design and tasks become more detailed, plans become more clear. • Estimates are dynamic and should be revised as more information becomes available or when requirements change. Source: Software Estimation: Demystifying the Black Art by Steve McConnell
  15. 15. The Cone of Uncertainty Source: Software Estimation: Demystifying the Black Art by Steve McConnell
  16. 16. Recognize a mismatch between a project’s business target and a project’s estimate for what it is: valuable risk information that the project might not be successful.
  17. 17. Case Studies
  18. 18. How I estimate software projects • Collect as much information about the project as possible. You will need at least several meetings with a customer to understand his needs. Remember about the Cone of Uncertainty. Try to kill everything that is not clear. • Good if mockups and UI design are ready, if not start initial Product Design Sprint creating User Stories, Mockups, and UI Design. • I create a Work Breakdown Structure (WBS). During the initiation and planning it helps organize task structure; double-check if something is missing; and control project Scope on later project stages. • Count first. We count Web pages, and functionality (User Stories) to understand the project size. • When a team is already known invite everyone into the estimation exercise (works for small and medium projects). Team estimation is a very good team building exercise; it is easier to make a commitment when you do the estimation and it is proven that group estimations are more accurate.
  19. 19. • Budget expectations • Schedule expectations • Functional Requirements • Non-functional requirements Collect • Mockups • UI • User Stories • WBS • Technology stack • Database structure • Application architecture Design • Make sure that something you have designed is something that is expected by a customer. Validate • Functionality • WBS items • Web pages • Proposal pages :) Count • Implement a Law of large number. • Involve Project Team. • Multiply on your team index. Estimate Product Specification Law of Large Number (15-20 items) Team index Count
  20. 20. Define your customer needs, schedule and budget early. Share your thoughts openly. (Raboph Case Study)
  21. 21. Wristo Project, Historical data implementation Number of pages: 6 Effort: 435 hours Effort per page: 72,5 hours Cost calculation= Number of pages x 72,5 x Diseconomy of Scale Index x Hourly Rate
  22. 22. Example of Bottom Up estimation
  23. 23. Remember about Indians, Chinese and the rest of the world (Manmeet story)
  24. 24. Thank You! Questions and ideas are welcome!
  • MohammadBagherSeifol

    Jan. 10, 2018
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    Oct. 15, 2015
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    Oct. 13, 2015
  • andriydenysov

    Oct. 13, 2015

Андрій Татчин "Software Project Estimation: Theory and Reality"

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