‹#› Hetbegintmeteenidee

THEGHOSTSOFLEGACYSOFTWARE

ILLUSTRATION:CharlesDickens:AChristmasCarol.InProse.BeingaGhostStoryofChristmas.WithIllustraMonsbyJohnLeech.London:Chapman&Hall,1843.FirstediMon.

@patricia_lago

‹#› Hetbegintmeteenidee

Legacy software doesn’t exist anymore – we just haven’t noticed

PHOTO:NIGELPARRY

PATRICIALAGO©2016

‹#› Hetbegintmeteenidee

Are we looking at the right problems?

DorianGray(2009),themoMonpicture

PATRICIALAGO©2016

PATRICIALAGO©2016

ENIAC Programmers Project (1946) Photo: Corbis

MicrosoB (2016) experimenGng with underwater DC to beat the heat

(?)

Legacy of the past, present, and future

PATRICIALAGO©2016

Approaches to modernize the “legacy of the past”: activities

Academic: Arch-shaped approaches

Industrial: Bowl-shaped approaches

TransformaGon

Forward engineering Reverse engineering

IdenGfy target

Forward engineering

Reuse legacy

PATRICIALAGO©2016

Approaches to modernize the “legacy of the past”: knowledge conversions Industrial only

Insights from legacy

Map soluGons based on experience

Convert legacy architecture/design into to-be business processes

PATRICIALAGO©2016

Legacy of the present: create new value from pre-existing systems

•  Cloudenvironment

•  HosMng

•  Keys:•  Cloudservicemodel(IaaS,PaaS,SaaS)•  MigraMongranularity(full,parMal)

•  Seamless•  UnnoMceabletocustomers•  DrivenbyobjecMvecriteria(incl.risksandbenefits)

A. Efremovska & P. Lago, From Legacy to Cloud: Risks and Benefits in SoBware Cloud MigraGon, 2016 (under submission)

PATRICIALAGO©2016

Legacy of the future: It’s all about longevity, seamless change, flexibility

•  Context-dependent•  Dealwithcomplexity(*)

(*) K. Dorst, Frame InnovaGon, MIT Press (2015)

OPEN (degrees of visibility)

DYNAMIC (conGnuous change)

COMPLEX (shared benefits and responsibiliGes)

NETWORKED (mulGple stakeholders)

Legacy of the future: Cyber-foraging optimizes functionality by resource discovery

Resource scarce environment

MissionimpossibleII(2000),themoMonpicture

Smart home

Legacy of the future: ARCHITECTURAL TACTICS FOR CYBER-FORAGING

G. Lewis & P. Lago, “Architectural TacGcs for Cyber-Foraging”, Journal of Systems and SoBware, Elsevier (2014)

Legacy of the future: DETECT context and usage

G. Lewis & P. Lago, “CharacterizaGon of Cyber-Foraging Usage Contexts”, In SoBware Architecture, Springer LNCS (2015)

Legacy of the future: DETECT context and usage

G. Lewis & P. Lago, “CharacterizaGon of Cyber-Foraging Usage Contexts”, In SoBware Architecture, Springer LNCS (2015)

Legacy of the future: QUALITY-DRIVEN INTELLIGENCE

Determine favorable condiGons (low bajery, presence surrogate, connecGvity)

•  Save bajery, decrease network communicaGon

•  Faster response Gme than local execuGon

•  Greater compuGng power in the surrogates

•  Decide on intermediate data caches

•  OpGmize network bandwidth

PATRICIALAGO©2016

PAST ProblemaGc systems with business value Port to new technological landscapes

Past, present, and future From LEGACY SOFTWARE to SOFTWARE LEGACY

FUTURE InnovaGon Create intelligent systems that are flexible, long-lived, and change seamlessly

PRESENT IntegraGon Create new value from pre-exisGng systems

The challenges from industry are others: agile refactoring, quality over funcGonality, context adaptaGon, knowledge management, business sustainability, societal impact

Thank you

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@patricia_lago

A Categorization of Green Practices used by Dutch Data Centers