Multi-Objective Software Effort Estimation Federica Sarro ! ! - - PowerPoint PPT Presentation

multi objective software effort estimation
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Multi-Objective Software Effort Estimation Federica Sarro ! ! - - PowerPoint PPT Presentation

Multi-Objective Software Effort Estimation Federica Sarro ! ! Senior Research Associate Dept. of Computer Science, CREST University College London ! f.sarro@ucl.ac.uk @f_sarro Multi-Objective Software Effort Estimation F. Sarro*, A.


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Federica Sarro!

!

Senior Research Associate

  • Dept. of Computer Science, CREST

University College London

!

f.sarro@ucl.ac.uk

@f_sarro

Multi-Objective Software Effort Estimation

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Multi-Objective Software Effort Estimation

  • F. Sarro*, A. Petrozziello**, M. Harman*

*CREST, Department of Computer Science, University College London, UK ** School of Computing, University of Portsmouth, UK

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Sarro et al. “Multi-Objective Software Effort Estimation”, ICSE’16

Process of predicting the most realistic amount

  • f effort required to realise a software project

(effort usually quantified in person-hours/person-months)

Software Development Effort Estimation

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Would you ever start producing anything without knowing the cost?

fluck.de

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Sarro et al. “Multi-Objective Software Effort Estimation”, ICSE’16

Why is it Important?

Project Scheduling /Staffing Project Bidding

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Why is it Difficult?

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Sarro et al. “Multi-Objective Software Effort Estimation”, ICSE’16

Options for Estimation

Experts tend to under-estimate

  • K. Molkken and M. Jorgensen. A review of surveys on software effort estimation. ISESE’03.
  • S. McConnell. Software Estimation: Demystifying the Black Art. Microsoft Press, 2006

40% 30%

Predictions of project effort lie within 30%-40% of the true value

What is the margin of error?

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Sarro et al. “Multi-Objective Software Effort Estimation”, ICSE’16

Options for Estimation

Predictio Deriving

Regression-based Search-based Analogy-based

{

Experts tend to under-estimate within 30%-40% of the true value

Data Driven ! Methods

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Sarro et al. “Multi-Objective Software Effort Estimation”, ICSE’16

Options for Estimation

Predictio Deriving

Data Driven ! Methods

Linear Regression Stepwise Regression Manual Stepwise Regression Support Vector Regression Classification and Regression Trees Case-based Reasoning K-Nearest Neighbours Genetic Algorithms Genetic Programming Tabu Search Simulated Annealing …

… still unable to par human-estimates!

After ~30 years of research…

{

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Confidence Guided Effort Estimation (CoGEE)

Estimation Uncertainty Estimation Error

CoGEE is a multi-objective evolutionary approach that seeks to build robust estimation models

Estimation Uncertainty Estimation Error

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Novelty of Our Approach

  • F. Ferrucci, M. Harman, F. Sarro, "Search-Based Software Project Management” in Software Project Management in a Changing World, G.Ruhe and C. Wholin (Editors), Springer, 2014

All previous evolutionary approaches sought to improve only point estimates none of them was clearly better than the state-of-the-art none of them parred human-expert estimates

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Sarro et al. “Multi-Objective Software Effort Estimation”, ICSE’16

CoGEE realised as a Non-dominated Sorting Genetic Algorithm- II (NSGAII) Compared VS. 3 baselines 3 state-of-the-art effort estimators 3 alternative single/multi-objective formulations

!

5 industrial datasets from the PROMISE repository (724 projects)

Empirical Evaluation

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  • RQ3. Benefits from Multi-
  • bjective Formulation
  • RQ4. Comparison to

Industrial Practices RQ1.! Sanity Check

  • RQ2. State of the Art

Benchmark

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Sarro et al. “Multi-Objective Software Effort Estimation”, ICSE’16

  • RQ4. Comparison to Industrial Practices

How does our approach, CoGEE, compare to human-expert-based estimates?

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Sarro et al. “Multi-Objective Software Effort Estimation”, ICSE’16

  • RQ4. Comparison to Industrial Practices

Overrun

Human-expert-based predictions of project efgort lie within 30% and 40% of the true value

The evidence for these thresholds comes from a survey of current industry practices by Molkken and Jørgensen

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Sarro et al. “Multi-Objective Software Effort Estimation”, ICSE’16

  • RQ4. Comparison to Industrial Practices

Overrun

The median error of CoGEE lies within both thresholds for all the datasets

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Sarro et al. “Multi-Objective Software Effort Estimation”, ICSE’16

  • RQ4. Comparison to Industrial Practices

This is not always true for the state-of-the-art approaches

Overrun

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Sarro et al. “Multi-Objective Software Effort Estimation”, ICSE’16

  • RQ4. Comparison to Industrial Practices

Overrun

CoGEE provides human-competitive results! CoGEE outperforms the state-of-the-art techniques!

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Sarro et al. “Multi-Objective Software Effort Estimation”, ICSE’16

Our proposed bi-objective evolutionary algorithm

Creates a new state-of-the-art that pars currently claimed human-expert estimates (RQ4) Outperforms scientific approaches previous published

(significantly and with medium and large effect size for all the datasets considered)

3 baselines (RQ1) 3 state-of-the-art methods (RQ2) 3 alternative single/multi-objective formulations (RQ3)

Empirical Results

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Sarro et al. “Multi-Objective Software Effort Estimation”, ICSE’16

Criteria Satisfied by Our Work

(G) The result solves a problem of indisputable difficulty in its field

! !

(E) The result is equal to or better than the most recent human-created solution to a long-standing problem for which there has been a succession of increasingly better human-created solutions

! !

(D) The result is publishable in its own right as a new scientific result independent of the fact that the result was mechanically created

! !

(B) The result is better than a result that was accepted as a new scientific result at the time when it was published in a peer-reviewed scientific journal

! !

(F) The result is equal to or better than a result that was considered an achievement in its field at the time it was first discovered

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Breakthrough results published in ICSE’16 top tier SE conference Thorough empirical study (724 real-word projects) Novelty

Estimation Uncertainty Estimation Error

Advances the state of the art

Sarro et al. “Multi-Objective Software Effort Estimation”, ICSE’16

Human-competitive results to a long-standing and diffjcult problem

Why our entry is the “best”

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Multi-Objective Software Effort Estimation

  • F. Sarro, A. Petrozziello, M. Harman

@f_sarro

http://www0.cs.ucl.ac.uk/staff/F.Sarro/projects/CoGEE/