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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML xmlns:o = "urn:schemas-microsoft-com:office:office"><HEAD><TITLE>Question about evolution vs replacement of classes.</TITLE> <META http-equiv=Content-Type content="text/html; charset=us-ascii"> <META content="MSHTML 6.00.2900.2912" name=GENERATOR></HEAD> <BODY> <DIV dir=ltr align=left>This has not climbed onto the CIM Core agenda yet.  Much urgent business in front of it.  (The original message went to entire Core group.  Second msg only to chair.  I will reword more strongly and resend to group.)  </DIV> <DIV dir=ltr align=left> </DIV> <DIV dir=ltr align=left>rick</DIV> <DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left> <HR tabIndex=-1> From: Landau, Richard Sent: Tuesday, June 06, 2006 17:40 To: 'crandall@brocade.com' Subject: FW: [wg-cimcore] Question about evolution vs replacement of classes. </DIV> <DIV></DIV> <DIV dir=ltr align=left> John, can we put this question that I posed on the Core agenda, please, for a short discussion in the near future.  Here's a short version just to get the idea across. <o:p> </o:p> If I add this many properties to a class, is it still the same class?             1        Y     N<o:p></o:p>           2        Y     N<o:p></o:p>           5        Y     N<o:p></o:p>         10        Y     N<o:p></o:p>         20        Y     N<o:p></o:p>         50        Y     N<o:p></o:p>       100        Y     N <o:p> </o:p> Is there an obvious breaking point?  Is there a breaking point at all?  Or is it reasonable to add lots of properties that were mistakenly left out in the first draft?   <o:p> </o:p> Thanks. <o:p> </o:p> rick <o:p> </o:p></DIV> <DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left> <HR tabIndex=-1> From: Richard_Landau@Dell.com [mailto:Richard_Landau@Dell.com] Sent: Friday, June 02, 2006 10:27 To: wg-cimcore@dmtf.org Subject: [wg-cimcore] Question about evolution vs replacement of classes. </DIV> <DIV></DIV> (For discussion in mail threads or on the concall) Procedural question for CIM Core: How much can one change a class before it isn't the same class anymore?  In the PWG (Printer Working Group) work on updating the CIM printing classes, we have concluded that a couple of the classes will require major facelifts.  CIM_Printer, for example, currently expresses about thirty properties.  A few of these will be deprecated and moved to CIM_PrintService, but the real question concerns properties that it does not currently express at all.  The industry model of a printer device includes a *lot* of properties that are not currently in CIM_Printer.  We will certainly attempt to reduce the number by collecting many of the properties into Capabilites and Settings classes, and perhaps by splitting some features into other separate classes (but not to the point of hyper-normalization).  Even so, the size of the class is likely to double.  So the question is, Is it plausible to add twenty, or thirty, or more properties to a class and still call it the same class?  - Shall we proceed on the assumption that we are simply going to improve CIM_Printer (and the others)? - Do classes ever revert from final status to experimental status because of such changes? - Will Core insist that we define an entirely new class, e.g., CIM_PrintDevice, with all the new properties and then deprecate the old class in favor of the new one?  I'm not asking for a decision of any sort at this point, but for a sense of the working group's process in such cases.  Thanks. rick ---------------------- Richard_Landau(at)dell(dot)com, Stds & System Mgt Arch, CTO Office +1-512-728-9023, One Dell Way, RR5-3 MS 8509, Round Rock, TX 78682 </BODY></HTML>