A Road Map. Software Engineering, Programming, and SCM

Transcription

1 Software Cofiguratio Maagemet A Road Map Jacky Estublier Greoble Uiversity - Frace 1 Software Egieerig, Programmig, ad SCM I the Small I the Large I the May I the Wide Programmig Laguages Compositio Buildig Variatio Evolutio Cocurret Eg. Distributed Eg. Cofiguratio Maagemet Process Support Deploymet, Web Remote dev Software Product Activities 2

2 What is CM CM is the CONTROL of the EVOLUTION of COMPLEX systems Ay complex system has : u Large umber of compoets ad their versios u Large umber of people ivolved (up to 1000) u Very hard time costraits (cycle dow to 4 moth) u Log product life duratio (10 to 20 years) Goal: Keep evolvig product uder cotrol ad help satisfy delays ad quality costraits 3 Cofiguratio Maagemet Maagig a repository of compoets Product ad versio Maagemet Help egieers i their usual activities Work Space ad tool cotrol Process cotrol ad support Chage cotrol & Cooperative work 4

3 Compoet repository:versio cotrol early 70s Brach Variat Successor RŽvisio History maagemet Delta (space savig) Multi-user ÒcotrolÓ Mergig Still the base of almost all SCM systems. 5 Versioig priciples Questio: Why are 2 objects versios of each other u They have somethig i commo (but what?) u They are differet (i what?). With curret tools the aswer is: u They share a large umber of lies, u They have some lies which are differet 6

4 Versio Set A group of chages has a logical ame (BugFix21) A specific release R2 ca be built from a previous oe R1 u R2 = R1 + BugFix21 + Extetio2 Ð Extetio3 We ca build versios that ever existed before! Higher coceptual level, easier to uderstad É For log preseted as the opposite to the versio tree Is becomig available i ew tools, with a versio tree. 7 Compoet repository: Product models Data Model : files ad directories We eed a good DB oe (icl. Relatioships). Product Model : System Model (80s) : architecture / compositio of a cofiguratio : Relatioship betwee compoets, depedecies, compatibility costraits, É (MIL, ADL). Most ofte oly a Makefile cotais that iformatio!!. 8

5 Help egieers: Selectio/Buildig Degree of geericity Degree of Bidig SCM Selectio iler Comp Liker Loader Compoet Variat Revisio Compilig Likig Loadig Architecture Model (ADL?) System Model Boud Model But still Coditioal Compi. Biary likable Biary locatable Memory Image Dy. Lib. Executable Image 9 ADL SCM Cof. CDS Cof. Software MaagemetDistr. Syst. Architecture Compositio Behaviour Cosistecy Buildig Versioig Selectio Covergece, itžgratio, complemet, iteroperability??. 10

6 Help egieers: Work Space Cotrol Work Spaces Compoet Repository NT view Uix View DB view Problem: Defie ad cotrol each arrow: Cocurret Egieerig cotrol 11 Curret Limitatios A cetral data base as repository. => Severe scalability ad efficiecy limitatios. Too low level product models Sigle rigid projectio. Cocurret work defiitio ad cotrol => No explicit defiitio, No high level cocepts => No way to eforce policies => Strog limitatios i distributed work 12

7 Process Cotrol ad Support Good kowledge ad cotrol of the software process is madatory for quality, cost ad delay predictability. FChage Cotrol. Well idetified ad formalized, => Each SCM tool proposes a solutio. FCocurret egieerig Team coordiatio ad sychroizatio. => No satisfactory propositio. FOthers : Busiess, admiistratio, orgaizatio => Weak ad overlaps with other tools. 13 State of Practice i SCM A process is described by a ÒState Trasitio DiagramÓ (STD) of the product. Etered IReview Assiged Resolved Cocluded Forwarded Defered Rejected It is a fie graied approach, but too low level. 14

8 Global assessmet Stregth : A successful techology because.. u It does ot take ito accout the sytax ad sematics of programmig laguages, applicatios, É 4 => Simple, geeric ad efficiet tools. 4 => Heuristics proved very effective. SCM is a pragmatic approach to solve SE problems. Weakess u It does ot take ito accout the sytax ad sematics of programmig laguages, applicatios, É 4 => No correctess criteria. 4 => Fuctioalities are limited. 15 Challeges 1 : Iteroperability A growig umber of tools iclude : Fa data repository, versioig, cocurrecy cotrol Example : most 4GL tools, PDM tools, editig tools Fprocess support Example : MS Project, Lotus, workflow, É Ad the icreasig umber of COTS tools, the icreasig eed to make iteroperate tools /activities. SCM tools must be desiged as a compoet which iteracts with may others, both for data AND process cotrol reasos. 16

9 Challege 2 : PDM v.s. SCM The icreased part of software i ay idustrial product The eed to develop cosistetly software ad hardware Icreasig overlap / coflict with PDM tools u May similarities but u May differeces É Noe ca preted to do both well. There is a eed to recocile these worlds. How? u Itegratio u Cooperatio u Extesio É 17 Challeges 3 : Remote developmet The gap betwee local, distributed ad remote developmet should (almost) disappear. The virtual eterprise (distributed ad heterogeeous) rises ow problems. Issues : Efficiecy, scalability, remote cocurret egieerig cotrol, heterogeeity, É 18

10 Challeges 4 : New domais New applicatios : ex Maagig web pages Potetially a larger market tha Soft developmet New / differet issues more pages (x10, x100) faster chages (daily) more (udisciplied) cotributors (x100) cotributors are ot soft. Professioals Who will take that market : Documet maagemet tools, SCM tools, others?. 19 Challeges 5 : Complexity The permaet tedecy to iclude more ad more aspects FNew kid of applicatios (e.g. web based) FNew kid of issues (e.g. deploymet, virtual eterprise) FNew kid of requiremets (e.g. dy. Recofigurable appl) F+ Scalability ad more performace SCM systems have a tedecy to become too fat. A SCM system is a moolithic ad proprietary system. =>difficulties for iteroperability, icremetal itroductio, trasitios, evolutio, cost... 20

11 Perspectives I the 80s: Most cocepts ad techiques developed. u Versio cotrol (70s), Chage set. u Workspace cotrol, u Chage cotrol É But ad hoc tools, o DB support, weak usability. Early 90s u Process support u Better iterfaces, coverage É. u More professioally built Maturatio phase. 21 Perspective / Coclusio Late 90s. Despite the remaiig weakesses, mature ad successful. A essetial techology for successful SE projects... Oe of the few success i SE techology, but challeged É. Market (Ovum) $1 Billio i 98, 99: 25% Maiframe, 15-20% of workstatios ad 5-10% PC. $2 Billios i 2000 $3.3 Billios i