Architctur of th proposd standard Introduction Th goal of th nw standardisation projct is th dvlopmnt of a standard dscribing building srvics (.g.hvac) product catalogus basd on th xprincs mad with th VDI 3805 standard. VDI 3805 contains a numbr of lmnts which hav bn dvlopd to support th modling of product catalogus. But many of ths lmnts ar usful also in othr contxts, so that it is not th goal to tak this standard as is, but to intgrat th concpts of VDI 3805 into BIM standards to mak thm also availabl for systms using th BIM mthodologis. Nvrthlss,thr xist faturs which hav to b dscribd sparatly in nw standards (rspctivly Parts of a standard) bcaus no appropriat BIM mthodology is availabl yt or bcaus spcial mans ar rquird for th original purpos of catalogu xchang. In this documnt, th lmnts of a standard ar dscribd which ar ndd to covr all th concpts providd by VDI 3805. In addition, th rlationships to th xisting BIM standards ar dscribd.
Elmnts of VDI 3805 and thir rlationships to BIM standards VDI 3805 in Building Data Cycl Th main constitunt parts of VDI 3805 ar dpictd in Figur 1 and dscribd in th following paragraphs: Configurations/ variantsstructur / paramtrics Manufacturrcatalogu with bhaviour informaton VDI 3805 Manufacturr Exchang format Mapping old to nw format DIN proprty srvr / IFD dfinitions Slctionof product I D M Plannr Singl VDI 3805 product intgratd in IFC Information / data about th building Gomtry rpr Algorithms Figur 1: Constitunt parts of VDI 3805 Th main purpos of VDI 3805 is th rprsntation of product catalogus of building srvics quipmnt manufacturrs. Thy normally put thir products (which might b mor than on million) into a singl VDI 3805 fil which can b snt to or downloadd by th dsignr of a building srvics systm. Th dsignrs hav to slct from th millions of products in th catalogu that product which fulfills thir rquirmnts. Th information about that product is thn xtractd from th catalogu and importd into thir CAD/CAE systm so that th dsignrs can do all rquird calculations and simulations with th data of th VDI 3805 fil. Th information may also b transfrrd into an IFC rprsntation and intgratd into th complt modl of th building. An initial mapping from VDI 3805 to IFC has alrady bn cratd and can b usd in softwar applications. This mapping xrcis basically ld to an addition of proprtis to IFC bcaus IFC dos not provid tchnical data on such a dp lvl as it is rquird for calculation and simulation of building srvics systms in a CAE systm. This usag of VDI 3805 is also shown in Figur 2: Whras th BIM documnt (BIM = building information modl) contains all data dscribing th whol building covring all lif cycl phass lik planning, constructing and building managmnt, tc., th VDI 3805 contains th manufacturr
catalogu of building srvics products which can b us to import product data into CAD/CAE systms and into th BIM modl.
Building Ownr s Data: Rquirmnts, Rstrictions Manufacturr s Data: Product catalogus Architct s Data: Walls, Floors, Cilings, Doors, Windows, Roofs VDI 3805 Building Srvics Dsignr's Data: Pips, Fittings, Hatrs, Radiators, Valvs, Air-Outlts Constructor s Data: Opnings, Hangings, Flangs FM Data: Claning Aras, Maintn. intrvals, Spar parts BIM Data (IFC) Archiv, Documntation Figur 2: VDI 3805 in th building lif cycl Dsignrs xtract singl products from th catalogu in th VDI 3805 data fil to insrt it into thir building srvics modl. Th individual product modl of th slctd product with all its tchnical and gomtrical data can thn b mbddd in th BIM modl. Using th BIM data, dsignrs hav full EDP accss to product data. In th sam way FM managrs can ordr corrct rplacmnt products. Also, th dsignrs of xtnsions to xisting building srvics systms can accss data with full tchnical contnt. Thy can rbuild thir building srvics modl and calculat and simulat it togthr with th nw xtnsions. This intgration procss of slctd product from th VDI 3805 into th plant modl of th CAE systm and into th BIM is illustratd in Figur 3:
Manufacturr s Data: Typ sris of products (pips, fittings, radiators, valvs, hatrs, air-opnings VDI 3805 Product catalogu data Including millions of product variants CAE-Softwar-Systms: Slction and configuration of singl products from VDI 3805 product catalogu Layout and calculations with manufacturr s algorithms BS Plannr s Data: Plants consisting of discrt palpabl products (pips, fittings, radiators, valvs ) VDI 3805 Product data mbddd in BIM plant modls l a u n a M ry liv D n tio a rm fo In in fin d to s c ro P ) M (ID Archiv, Documntation Furthr rlationships with BIM (s Figur 1): Figur 3: Intgration of product data from th VDI 3805 fil into th BIM To achiv long trm introprability with othr standards it is important to clarly dfin th concpts usd in VDI 3805. For this purpos, currntly a pilot projct dscribs som of th proprtis and objcts of VDI 3805 for th DIN proprty srvr basd on th modl of ISO 13584 (PLIB). IFD has th sam undrlying goal as th DIN srvr, dscribing th trminology and maning of proprtis and objcts to giv maning to lmnts of xchang formats and data modls. Thus, th work don for th DIN srvr will srv as an initial stp for th dfinition of product catgoris and proprtis in IFD, and for th futur, it is xpctd that th two projcts will bnfit from ach othr. VDI 3805 is usd by many manufacturrs to provid thir catalogus and also intgratd in a numbr of CAE systms. But th procsss in which this information is usd ar not yt xplicitly dscribd. Such a dscription could rval mor possibl usag scnarios and allow a bttr intgration of th standard into businss procsss. IDM provids a good basis to dscrib th procsss and to intgrat thm with xchang rquirmnts and actual data modls. Thr ar som furthr lmnts in VDI 3805 which probably cannot b handld dirctly by mbdding thm into on of th BIM standards. Ths lmnts ar th rd boxs of Figur 1: Th VDI standard contains mchanisms to dscrib possibl products as a configuration of proprtis and sub objcts which ar part of th VDI 3805. This mchanism of dscribing diffrnt variants in a paramtric way has to b rtaind. Currntly, th VDI 3805 fils ar basd on a static fil structur: data lmnts ar idntifid by thir position in a fil. Hr it is th goal to dvlop an xchang format in form of an XML schma which rtains th advantag of th compact VDI 3805 fils but rcogniss th currnt mchanisms usd for data xchang. VDI 3805 provids two lvls of dtails of gomtry. Th first lvl provids a simpl gomtry rprsntation of thos gomtrical lmnts which ar ndd for th rprsntation of building srvics products and thir intgration into a building srvics
systm. It is important for th usrs to kp th gomtry as simpl as possibl. Furthrmor a scond lvl provids a mor dtaild gomtry rprsntation to fulfill also th rquirmnts of product markting. Both gomtry lvls do not fit to th IFC gomtry: Whras IFC rprsnts gomtry by a static (boundary) modl, VDI 3805 uss a paramtrizabl CSG rprsntation (constructiv solid gomtry). It contains som basic 3D lmnts (primitivs) which can b combind by various oprators to crat th intndd gomtry. CSG is th gomtry rprsntation mthod which is usd in most CAD systms for mchanical nginring. Th basic building blocks dfind in VDI 3805 ar spcifically tailord to th nds of building srvcis applications; in particular, thy covr lmnts which cannot b gnratd from th usually providd primitivs and normal CSG oprations. Th primary goal of VDI 3805 is to allow building srvics dsignrs to us th calculation algorithms providd by th dvic manufacturrs in thir systm analysis. Thrfor VDI 3805 contains a simpl way of xprssing ths functions as psudo cod. This is an important lmnt which has to b rtaind. Forsn Organisation of th standard To com to an organisation of th lmnts to b dscribd, w can start (at last) from two angls: Gnric and product group spcific information From th dscriptions in th prvious chaptr it can b concludd that w nd two typs of lmnts: gnric lmnts which form th basis of th standard and can b applid for all product aras: o rprsntation of gomtris o rprsntation of algorithms and drivabl proprtis o mchanisms for variant combination in an ovrall composition hirarchy o fundamntal XML schma for product data xchang product spcific lmnts spcifying product ara or product group spcific contnt and structurs which ar rquird to allow th xchang of all ncssary faturs of th rspctiv products IDM orintd structurs IDM provids a structuring of information around spcific aras of us. A possibl ovrall vision for th IDM structuring of VDI 3805 is dpictd in Figur 4.
BR functions? IDM PM procss dscriptions of Doc #001 ER Objct typs to b xchangd (possibly spcific for Parts of VDI 3805) Proprtis which ar mandatory concpts which ar rquird outsid of IFC/IFD FP (1) MappingsVDI 3805 IFC, if possibl (2) Dfinition of IFD lmnts whr (1) is not availabl, mbddingin IFC (3) othrs,.g. linkagof xisting VDI 3805 lmnts with IFD dfinitions Figur 4: Possibl IDM structur for VDI 3805 Businss Ruls (BR): It has to b dcidd whthr som of th lmnts of VDI 3805 can b modlld as IDM businss ruls. On suggstion was to dscrib VDI 3805 functions as businss ruls, and thr xist othr xampls of rcommndations in VDI 3805 (.g. th rcommndd combination of gomtrical information as dscribd in Part 5 of VDI 3805) which might b sn as businss ruls. Procss Mapping (PM): A documnt has alrady bn dvlopd which dscribs th ovrall procsss in which VDI 3805 and th nw standard is supposd to b usd. Exchang Rquirmnts (ER): Exchang Rquirmnts dscrib what is rquird for a valid xchang of information. Hr it is xpctd that for diffrnt product aras th product groups ar spcifid as wll as th information (i.. proprtis) which nd to b givn for a product group. Othr information might b addd as rquird,.g. spcific structural spcialitis which only apply for this spcific product ara. Functional Parts (FP): Th Functional Parts dscrib how th rquirmnts dfind in th prvious IDM sctions ar implmntd. For a VDI 3805 IDM it is forsn that hr th mapping of VDI 3805 lmnts to IFC ar dfind, as far as this is possibl, and that for th othr lmnts dfinitions in IFD ar givn. This information should b mbddd in IFC in th first stp, but in th futur, it might b migratd into cor IFC vn if it is xpctd that this will tak a long tim. Anothr pic of information givn hr could b a formal connction of th concpts in IFC and IFD to th lmnts of th XML xchang structur or a connction of th currnt VDI 3805 lmnts with th IFD lmnts thus making th currnt VDI 3805 xchang structur a part of th IDM. Combind structur proposd for th standard Th following structur can b sn as a combination of th two approachs: 1. Ovrall Parts: a. Procss Map b. Gomtry Rprsntation
c. Rprsntation of algorithms and drivabl proprtis d. Mchanisms for combining variants in an ovrall composition hirarchy. Basic XML schma for product data xchang 2. Product ara spcific Parts: Pr product ara (covrd in on of th Parts of VDI 3805) an IDM will b dvlopd containing th following lmnts: a. Rfrnc to th ovrall Procss Map b. Exchang Rquirmnts: i. List of product groups ii. List of proprtis for ach product group iii. List of mandatory proprtis for ach product group c. Functional Parts: i. Mapping to IFC whr availabl ii. Mapping to IFD iii. Connction to XML structur (if that cannot b don on a gnric lvl) It is proposd that th ovrall parts gt on digit part numbrs (1 9), and that th spcific IDMs gt two digit part numbrs (10 99).