Integrating Collaborative Requirements Negotiation and

Prioritization Processes: A Match Made in Heaven

Nupul KukrejaAnnual Research Review

14th March 2013

Outline

1• Motivation

2• High-level overview

3• Background and Related work

4• Two-step Prioritization Approach

5• Evaluation and Results

Motivation• Not enough time and money to implement

all requirements– Need to prioritize requirements w.r.t. budget and schedule

constraints• High coordination and transaction costs to ascertain

requirement priorities or reprioritizing new/changed requirements

• Too many ties using MoSCoW or 1-10 scoring– Assumes stakeholders can correctly score requirements as

per intrinsic value– Difficult to ascertain value of new/changed requirements in

relation to others

SolutionValue-Based Requirements Prioritization (VBRP)!• Stakeholders select the most valuable requirements

for implementation– “Value lies in the eyes of the beholder” – but can be

captured with some effort• Decision theory folks working on this for a long time

– Some models (e.g. AHP) have been used for requirements prioritization with varying degrees of success

• Propose a ‘lightweight’ two-step approach based on TOPSIS (Technique of Ordered Preference by Similarity to Ideal Solution)

Two-step Approach – Overview

System

MMF-1Req 1

Req 2

MMF-2Req 3

Req 4

MMF-3Req 5

Req 6Prioritize w.r.t. business goals

(TOPSIS)

Prioritize w.r.t. business value,

relative penalty & ease of realization

(TOPSIS)

Decompose System into

MMFs

Decompose MMFs into low level requirements

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Ideal Alternative (S’)

TOPSIS (What?)

Criterion 1

Criterion 2

Alternative 1

Alternative 2Non-Ideal Alternative (S*)

Aim: Rank order alternatives by their ‘closeness to ideal’ and ‘distance from non-ideal’Criterion: Has ‘direction of preference’ i.e. more/less of the criterion is preferredIdeal: Best score for each criterion Non-ideal: Worst score for each criterion

TOPSIS (Why?)

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Winbook• A collaborative, social networking based tool

for requirements brainstorming similar to facebook…

• …with requirements organization using color-coded labels similar to Gmail…

• …to collaboratively converge on software system requirements reaching win-win equilibrium (based on Theory-W)…

• …by keeping it short and simple like XP’s user stories!

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TOPSIS integrated with Winbook in v2.0

TWO-STEP PRIORITIZATION

0. Goals Articulation & Prioritization• WinWin methodology assumes project goals

are captured and prioritized before commencing “WinWin Negotiations”

• Added a “precursor” step for capturing and prioritizing goals prior to initiating negotiations

• Goals captured in Winbook and prioritized using success sliders

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1. MMF Decomposition• Top-down decomposition of system into

Minimum Marketable Features (MMF)– Units of software value creation– Components of intrinsic marketable value

• Prioritize MMFs against project goals:– MMFs scored against each goal on a 1-9 scale

(1 = MMF has little to no contribution in realizing the goal; 9 = MMF wholly contributes towards realizing the goal. Absolute scale okay too)

– MMF priorities ascertained by underlying TOPSIS algorithm

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MMFs are ‘leaves’ of tree

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MMFs

2. Win Condition Capture & Prioritization• Win Conditions (WCs): Stakeholders’ desired objectives

stated in an easy to understand manner and formalized where necessary (“functional” WCs captured in ‘user-story’ format)

• MMFs decomposed into constituent WCs• Win conditions prioritized against:– Business Value (1: low; 9: high)– Relative Penalty (1: low; 9: high)– Ease of Realization (Story-points/Fibonacci scale)

• WCs priorities also computed by TOPSIS and scaled by MMF they belong to(Similar GUI as previous slide)

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Two-Step PrioritizationGoals

Success Sliders

MMFs

Goal 1

Goal 2

…

Goal n

Requirements

Business Value

Relative Penalty

Ease of Realization

: Influences Priority Score

• MMFs influenced by business goals• Win condition scores influenced

by MMFs they belong to• Change in goal weights change

in requirement priorities• Dynamically (re)prioritizable

product backlog• Developers can ‘pull’ most

valuable requirements from (up-to-date prioritized) backlog

Evaluation & Results• Two-step approach deployed in software

engineering project course (CS577) @ USC since Fall 2011

• Empowered teams to perform sensitivity analyses:– Varying goal weights and gauging impact on MMFs/WCs– Varying criteria weights to ascertain high-value, high-risk

or complex WCs for prototyping• New requirements/changes comparable with

existing ones to ascertain optimum scope leading to channelized negotiation sessions

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Evaluation & Results (Cont’d)• Ability to have requirements backlog with

accompanying rationale for each requirement• TOPSIS-Winbook approach provided significant

improvements in organizing, updating and accessing captured rationale over previous versions of the WinWin negotiation systems

• Live traceability from goals to win conditions (and vice versa) vs. static traceability matrix– Makes explicit contribution of MMFs to goals (and

consequently WCs to goals)

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Limitations• TOPSIS rank reversals – inclusion of spurious

alternatives can change prioritization order of requirements– Not a major concern for cooperative teams (not intent

on gaming the system)– Cause of concern for negotiation among competitors

• Hierarchical prioritization may not agree with intuition/gut-feel– Teams manually account for discrepancies

• Prerequisites/dependencies not handled in current version of Winbook

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Conclusion• Two-step prioritization decouples business

(goals/MMF) prioritization from individual requirements

• Ability to quickly gauge impact of changing business goal priorities on individual requirements

• Provides dynamic reprioritizable product backlog for use in lean/agile/kanban projects

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Integrating a decision theory based prioritization framework with a collaborative requirements negotiation and management tool thus provides a rationale-backed prioritization of requirements allowing the stakeholders to channelize their negotiation and development efforts around the most valuable requirements.

A match truly made in heaven…

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Thank you!

Questions?