Handling Non-functionalRequirements in

Model-Driven Development:

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Outline

• Motivation and objective

• Research questions

• Context of the study

• Discussions and decisions

• Further details

• Conclusions and what’s next

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Motivation

NFRs: express conditions onthe behaviour of the system

MDD: software developmentbased on models

NFRs need to be managed by MDDprocesses, one way or another

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Background

Interest, timeliness, awareness

NFR-aware MDD processes

Evidence from practitioners dealing with NFR missing

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Objective

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In a nutshell• Investigating on: industrial practices in

dealing with NFRs in MDD processes• Empirical study survey based on semi-structured interviews

• European-wide 8 European countries involved at least 3 companies per country

• 3 research questions structured into 10 subquestions

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Research questionsRQ1 In which context is MDD adopted by companies?RQ2 To what extent do MDD approaches adopted by

companies support NFRs?RQ3 How do companies deal with NFRs when the

adopted MDD approach does not support them?

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Research questions – RQ1RQ1 In which context is MDD adopted by companies?

RQ1.1 What factors motivate the adoption of MDD?RQ1.2 Which types of NFRs are linked to these motivating factors?RQ1.3 To what extent are NFRs relevant for those projects that

adopt MDD?

RQ2 To what extent do MDD approaches adopted bycompanies support NFRs?

RQ3 How do companies deal with NFRs when theadopted MDD approach does not support them?

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Research questions – RQ2RQ1 In which context is MDD adopted by companies?RQ2 To what extent do MDD approaches adopted by

companies support NFRs?RQ2.1 Which types of NFRs are supported by the adopted MDD

approaches?RQ2.2 Which characteristics do these NFRs exhibit?RQ2.3 Which notations and tools are used for the supported types

of NFRs?RQ2.4 At which stages of the adopted MDD approach are these

NFRs handled?

RQ3 How do companies deal with NFRs when theadopted MDD approach does not support them?

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Research questions – RQ3RQ1 In which context is MDD adopted by companies?RQ2 To what extent do MDD approaches adopted by

companies support NFRs?RQ3 How do companies deal with NFRs when the

adopted MDD approach does not support them?RQ3.1 How are MDD approaches customized to take into account

the previously unsupported types of NFRs?RQ3.2 How do companies deal with an NFR which is not supported

by MDD?RQ3.3 To what extent are the drawbacks of dealing with

unsupported types of NFRs compensated by the benefits ofadopting MDD?

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Context – The team

• Collaborative approach one team per country wider population exploiting expertise

• Highly motivated no funding available (contributions welcome!)

• Lots of managerial issues see paper for details

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Context – The team

CoordinatorInterviewing partners

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Discussions and decisions (1)• Taxonomy of NFRs common taxonomy or ad-hoc classifications

Ask interviewees examples of NFRs Check if the company uses some

taxonomy

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Discussions and decisions (2)• Meaning of MDD for practitioners, the meaning may be diverse

Ask interviewees their concept Fit into the hierarchy MDA – MDD –

MDE – MBE

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Discussions and decisions (3)• Selection of companies independent or coordinated

Got a ranked list of candidates Balanced selection considering

domain, matureness, …

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Discussions and decisions (4)• Interview execution reconcile different situations

Interview in mother tongue Recording not mandatory Transcription to English

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The study – a survey

• Protocol according to (Ciolkowski et al. 2003):

Semi-structuredinterviews

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The study – protocol• Population and sampling non-probabilistic sampling of software companies track on using MDD in software projects interviewee with experience in at least 1 project

• Rigorous questionnaire design (Dillman 2014)• Data analysis basic descriptive analysis content analysis

• See paper for details on other issues

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The study – threats to validity• Internal validity understandability Dillman & piloting language transcription cross-check insufficient knowledge careful selection untruthful answers anonymous & explanations

• External: no generalization attempted• Conclusion interviewers’ bias documentation & meetings replicability documentation & CC-BY license

• Construct wrong methodology Ciolkowski misalignment with RQsmodel-based theory

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Conclusions• First large-scale study on practitioners’ work

with NFRs in MDD processes Potentially interesting to three communities

• RE, MDD, ESE

• RE:Next! was a great opportunity Feedback from reviewers (and attendees, we hope) Early visibility and awareness Internal deadline

• First of a series! Interest already expressed in South America

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What’s Next!• Study ready to be conducted

• Data collection finalized

• Data analysis completed

• Study report produced• Paper planning available

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Questions to the audience• Any insights on the management of NFRs in

practice in MDD projects?• Any tips on empirical studies involving several

research teams?• Any recommendations in data analysis?• …