DIAGNOSTIC AND
MAINTENANCE CONTROL SUBCOMMITTEE
07-D MEETING
Baltimore,
MD
September 15-16, 2007
Call to Order
Approval of Agenda
Reports
Chair's report
Secretary's report
Liaison Reports (CS, I&M, AES)
Brief presentations
Joint meetings as necessary with all working groups
New Recommended Practice for XML/EXPRESS Instance Document Validation
AI-ESTATE Status
Services proposal review
Items anticipated for later revision
XML schema review
Annex issues
Plans for ballot
SIMICA Discussions
Issue on PAR extension request (NESCOM)
Relationship between SIMICA effort and work in logistics community
Plans for QA review
Final edits on ballot draft
Prepare for ballot
MAI Discussions
Finalize XML schema
Document review
Plan for ballot
P1522 Re-organization
Future of document
Final Discussions on All Topics
Review Old Action Items
Review New Action Items
Set Time and Location of 08-A Meeting
Set Agenda for 08-A Meeting
Adjourn
The meeting was called to order at 9:00 by Mark Kaufman.
The call for patents, including the showing of mandatory slides, was completed at the SCC20 plenary meeting prior to the start of this meeting.
Agenda was modified and approved by the subcommittee.
Chair’s Report
P1232 PAR will remain active as long as the currently published standard is active. We have a comment on the P1636 PAR extension request. There is a concern from NESCOM about the size of the working group and the working group's ability to complete the standard within the extended period.
Secretary’s Report
Minutes of 07-C meeting were reviewed and approved.
Action Items and Open issues were reviewed and modified as appropriate.
Liaison Reports
CS liaison had nothing to report.
I&M liaison had nothing to report.
AES liaison had nothing to report.
P1522 Discussion
We still have not received any feedback from Bill Ross or Malcolm Brown. Bill Ross did say he wanted the NxTest IPT (especially ATS Framework Working Group) to review the standard. Mike Malesich indicated his willingness to have the working group review.
Bill had indicated in Madrid that he thought the weapon system developers and buyers are the ones that would be more interested in the standard. Malcolm Brown indicated that the UK MoD is in the process of updated Def Stan 0013 and that they might be able to use P1522.
SIMICA (P1636)
With the PAR extension request, we received a comment from NESCOM (Ronald C. Peterson). “Based on activity to date, it would be useful to receive some assurance that the relatively small working group will complete the draft and ballot within the two year period requested.”
Proposed Response: We identified seven active participants. There are numerous participants involved and providing input beyond the seven active ones. Much of this input drove the P1636.1 and P1636.2 standards. Note that P1636.1 has now been approved and P1636.2 will commence ballot shortly. These two standards have driven the completion of the umbrella standard being developed under this PAR. In addition, the draft is nearly complete. It was just not feasible to complete ballot within the time remaining. We expect to go to ballot by June 2008, as indicated in the extension request. This projection has not changed since we submitted our request.
The subcommittee chairs like the above and plan to submit it back to NESCOM.
It would be helpful to have more input from the logistics community. This is because of the tight coupling between the supply chain and the maintenance process. For example, an indication of a potential RTOK/CND problem is a spike in some inventory/part requirement. Tim called for all people to try to get people from the logistics community involved. This must happen before the next meeting, or it will be too late. That said, there was consensus that we need to keep the scope of SIMICA on diagnostic maturation. Specifically, we do not want SIMICA to become a “logistics” standard.
The QA review of SIMICA is complete. Barring further changes, the standard is ready to ballot. Assuming we get the extension on the PAR, we will attempt to obtain a logistics-based review of the information model. By the 08-A meeting, the standard will proceed to ballot with or without input from the logistics experts (contingent upon approval of the subcommittee).
AI-ESTATE (P1232)
We started to discuss the open action items for P1232 and whether or not the extended life of the PAR would permit us to include elements that would not have otherwise been included in the next revision. This led to the discussion on the order constraint. To summarize the discussion, it was decided that the precondition attribute of Action be removed and that the community make use of the preconditions/postconditions/states in ATML's TestDescription schema as interim solution. No action will be taken to modify the standard relative to ATML/TD; however, the issue of order constraints will be reconsidered on the next version or as an amendment to the standard.
We also discussed the validation approach (briefly). The general feel is that there would be benefit from the recommended practice, and it would be good to put a PAR in soon. The working group will discuss this after AUTOTESTCON and decide whether or not to put together a PAR between this and the next meeting.
We did an initial review of some of the 6.2 services. Some entities were identified that need “name” attributes.
Lots of discussion took place around loading and saving models. The consensus was that the save/loadModel and save/loadExchangeModel can be reduced to just the first set. (I.e., we don't need separate exchange format-specific services). To do this, the load service will be required to determine the type of file to be read (native format, part 21, or XML), and the save service must specify one of those three types. At the same time, there are two approaches to handling these services: one where an explicit path is specified, and one where just a name is provided and the reasoner manages file location. Both of these options will be supported. In addition, paths will be specified via URN.
There was some confusion over the purpose of set/restoreCheckpoint that may suggest an additional pair of services is required (e.g., set/restoreWaypoint). The checkpoint services are intended to support suspending and resuming a session or recovering from session failure. The waypoint services would be intended to support backing up to a defined step in the session trace. There was no consensus on how the managing of checkpoints was to be accomplished. It was referred back to the working group to determine who is in control (i.e., application vs. reasoner) and whether a file path needs to be specified.
It has been suggested that the model for selecting/specifying tests and applying outcomes should change. The current standard recommends a test (with select_test) and associates that test with the current step. Then the outcome of the test is applied for the state to be updated. If a test other than the one recommended is to be evaluated, it must be overridden with assign_tests. Under the new model, assign_tests would be deleted because there would no longer be an assumption that the chosen tests (actually actions) are automatically associated with a step. The association now occurs when the outcomes are assigned. A byproduct of this is that select_test becomes recommendActions and apply_outcomes operates on any action rather than just tests. In recommendActions, a list of actions is returned where the length of the list is specified, and the list is interpreted as a ranking of recommended actions. One or more of the recommended actions might be taken. If the full list of n actions cannot be provided, a shorter list will be returned without an error being generated.
Need to add a new service to permit the assertion of any outcome in the model.
The review of the service, getMostLikelyDiagnoses, was deferred until later.
The services, estimated_..._to_isolate/repair/resources have been referred back to the working group to put together a proposal explaining what they mean.
Should merge requestTestResourcesNeeded and requestRepairResourcesNeeded into requestActionResourcesNeeded.
For showSessionTrace, this is expected to be used as a way to play back all or part of a session during the diagnostic process. The current specification of STRING is weak but could be replaced with serialized XML. This needs to be fleshed out further rather than simply abandoned.
Darryl raised the question of whether or not the 6.1 services should be retained. Log 466 provides more detail. It seems to be premature to make this decision given some of the “advanced” use cases involving maturation or learning where multiple applications are interacting to make this happen.
P1232 (continued)
The started with a summary of the P1232 activities from Saturday. Michelle Harris led the discussion. The action items were reviewed again, and the models were tweaked and twiddled.
We started by finishing with the slides Darryl presented, focusing specifically on the probability issues. It was decided that an “ActualUsage” entity be added to the DCM to provide an “index” into the associated probability distributions from the CEM. This entity would include, at a minimum, attributes for time index, units, and identification of the top-most repair item. A requirement would be imposed that the usage implicitly “flows down” to child RepairItems. The entity would be shown as a list connected to Step. The list structure would impose an order of precedence in the event a child RepairItem has multiple parents. In this case, later “parents” in the list would have precedence (i.e., would override earlier parents). The attribute is placed on Step to permit usage to change through the session.
Discussion moved to conformance in an attempt to provide guidance. It was suggested that, if 6.1 services are to be provided, then there should be no differentiation between Core and Optional elements. In addition, even though the focus is shifting to conforming to reasoning models, all applications must be able to read all CEM elements (whether optional or not), even though they may not use them.
Two types of conformance are envisioned:
Model exchange (i.e., the model conforms)
Reasoner services
This is no different from the current standard; however, the question was raised about how/whether a reasoner conforms if its operation depends upon (i.e., requires) optional elements within a model. Three “levels” of conformance were identified:
Minimal/core elements and capabilities
Required elements plus optional to support added features, but the optional are not required.
Required elements plus optional to support added features, but the optional are required. In this case, the implementation would not be conformant.
In all cases, any application identifying that it implements some aspect of AI-ESTATE, whether claiming conformance or not, must specify any exceptions.
P1636.2 (MAI)
Joe Stanco walked through the current MAI schema.
During the review, it was pointed out that existing MAF systems incorporate a job status field. The MAF is not “generated” until the job status is complete; however, people can still access a MAF in process within the hosting information system. Therefore, it was suggested (and accepted) that a “MaintenanceActionStatus” complex type be added to the top level. This would include an enumeration of Open and Closed as well as a qualifier, which would be a string.
The schema was thoroughly reviewed and suggestions made for improvement.
Next we did a quick review of the structure of the MAI standard document.
Roadmap
The roadmap was reviewed and updated.
Users Guide
We need one.
Agenda Review
The agenda for the next meeting was put together and approved by the subcommittee.
The meeting adjourned at 4:00 pm.
|
Name |
Affiliation |
|
Day 1 |
Day 2 |
|---|---|---|---|---|
|
Alwardt, Tony |
Boeing |
X |
X |
|
|
Busch, Darryl |
Honeywell |
X |
X |
|
|
Ellis, Keith |
EADS Test & Engineering Services |
X |
|
|
|
Finklea, Ken |
DRS |
X |
X |
|
|
Frank, Brit |
US Army |
X |
X |
|
|
Gerstein, Bill |
Hamilton Sundstrand |
X |
X |
|
|
Harris, Michelle |
Lockheed-Martin |
X |
X |
|
|
Helton, Alicia |
Lockheed-Martin |
X |
X |
|
|
Kaufman, Mark |
US Navy |
X |
X |
|
|
Modi, Mukund |
NAVAIR |
X |
X |
|
|
Neag, Ion |
Reston Software |
X |
|
|
|
Ralph, John |
Northrop Grumman |
X |
X |
|
|
Schieber, Michel |
EADS Test & Engineering Services |
X |
X |
|
|
Sheppard, John |
Johns Hopkins University |
X |
X |
|
|
Stanco, Joe |
SSAI |
X |
X |
|
|
Stumptner, Markus |
University of South Australia |
X |
X |
|
|
Wilmering, Wilmering |
Boeing |
X |
X |
Old Action Items
Action Item 06C-3: Alicia Helton will examine the 1232 models for elements that may be related or duplicated in a P1636.x schema. Such identification will enable use to ensure consistency between the schemata and provide a mapping as necessary.
Status: OPEN
Action Item 06C-4: Pat Kalgren to use his AUTOTESTCON 2006 paper to start developing a prognostics annex for 1232. This paper will provide a set of definitions as a starting point.
Status: OPEN Michelle will contact Pat to see if this is still feasible
Action Item 07A-3: Darryl B. to obtain a description of the operational/environmental information from recording devices for a commercial platform relevant to diagnostics.
Status: OPEN
Action Item 07A-7: Darryl B, Tony A., and Alicia H. to provide a recommendation for specifying services via a transaction-based approach for P1232. The recommendation will also include specification of the 6.1 and 6.2 services.
Status: OPEN Specification still remains to be completed.
Action Item 07A-8: Darryl B. to complete a proposal for the XML schemas and validation approach for P1232.
Status: OPEN John R. added to action item to help Darryl. Validation approach to be moved to a separate recommended practice. XML schemas still need to be completed.
Action Item 07A-10: Darryl B. to provide proposed text for the conformance section of P1232.
Status: OPEN This has been re-assigned to Tim W. and Mark K.
Action Item 07A-12: Mark K. to draft a PAR for revising P1522.
Status: OPEN
Action Item 07A-13: P1232 working group co-chairs to prepare final draft of P1232 for April meeting.
Status: OPEN, Modified to be due electronically by January 15, 2008.
Action Item 07B-1: John S. and Tim W. to pursue data collection experts from the railroad and airframe (Boeing) industries to get involved in performance data standardization.
Status: CLOSED, Can't remember what this was about.
Action Item 07B-2: Joe S. to find an explanation and justification for the InventoryTransaction entity within the MAI schema.
Status: CLOSED
Action Item 07B-4: Joe S. and Mukund M. to provide a fleshed-out draft of the P1636.2 document.
Status: CLOSED
Action Item 07B-5: Joe S. and Mukund M. to re-examine the nature of the top-level discrepancy and how to represent that in MAI, specifically focusing on the issue of whether or not the current Cause element is properly/completely defined. For example, does Cause = Discrepancy? Probably not. There may be many causes that lead to the discrepancy.
Status: CLOSED
Action Item 07B-6: Michelle H. to add text to the P1232 standard expressing that the focus of the models is to define semantics and to facilitate information exchange. As a result, it is possible, if not likely, that an instantiation of the model will not be optimized for computational purposes (wordsmithed for clarity).
Status: OPEN
Action Item 07B-7: Michelle H. to investigate how they are storing the probabilities in the probability tables. Two questions to be resolved: 1) Are the diagnosis outcome probabilities only priors, therefore, only requiring one value per outcome? 2) How are the state values ordered in the likelihoods associated with the test outcome probabilities? This ordering needs to be specified in the standard to ensure exchangeability.
Status: OPEN The answer to the first question is “Yes.” Second part assigned to Alicia.
Action Item 07C-1: Mark K. to modify “nattergram” approach to be more personal.
Status: CLOSED
Action Item 07C-2: Tim W. to ping Malcolm Brown on status of 1522 needs in UK MoD.
Status: CLOSED
Action Item 07C-3: John S. to ping Bill Ross on status of 1522 needs in US DoD.
Status: CLOSED
Action Item 07C-4: John S. to update the EXPRESS schemata to reflected modifications in structure and definitions coming out of the ad hoc 1232 committee.
Status: CLOSED
Action Item 07C-5: Brit Frank to do a detailed review of the current draft of SIMICA for the September DMC meeting.
Status: CLOSED
Action Item 07C-6: Brit Frank to complete a QA review of the P1232 draft prior to submission to MEC.
Status: OPEN
Action Item 07C-7: John S. to talk to Bill Ash about the process for extending the validity of a published standard and to discuss, specifically, the extension for 1232-2002.
Status: CLOSED
New Action Items
Action Item 07D-1: Tim W., John R., Michelle H., and Mukund M. to contact logistics experts/SMEs at their respective organizations to review the SIMICA information model to determine if there are any blatant omissions or issues with the current model as well as solicit involvement in subsequent work on the standards. By the 08-A meeting, the standard will proceed with or without input to ballot (contingent upon approval of the subcommittee).
Status: OPEN
Action Item 07D-2: John S. to add “name” attributes to: DCM.Session and CEM.Resource.
Status: OPEN
Action Item 07D-3: Darryl B. to write a constraint that Action.Cost.CostCategories in the CEM should be unique.
Status: OPEN
Action Item 07D-4: Darryl B. to write an introduction to ISO 10303-21 as an informative annex to P1232.
Status: OPEN
Action Item 07D-5: John S. to modify the DCM to include an “ActualUsage” entity as described in the 07-D minutes.
Status: OPEN
Action Item 07D-6: Darryl B. to add relevant services to support “ActualUsage.”
Status: OPEN
Action Item 07D-7: Alicia H. and Darryl B. to develop a service for asserting outcomes.
Status: OPEN
Action Item 07D-8: Joe S. to add a complex type to the top level of MAI to capture MaintenanceActionStatus. This would include an enumeration of Open/Closed as well as a string qualifier.
Status: OPEN
Action Item 07D-9: Joe S. to define a Personnel complex type. Once created, it will be added as a child of Resources. The rest of the schema will then be cleaned up wherever personnel are involved.
Status: OPEN
Action Item 07D-10: Joe S. to define a new complex type capturing the current structure involving AssociatedDiagnosticResult and the choice of Observation, AssociatedTestResults, and AssociatedFailureCode. Then create a choice under ReactiveMaintance that chooses between a reference to an MAI at the next level up or to this complex type. The complex type is called “Cause.”
Status: OPEN
Action Item 07D-11: Joe S. to modify the schema to represent the following sequence of events: 1) Document information received from prior level (or something that initiated this maintenance action), 2) Perform sequence of events and collect information (e.g., cause-action-cause-action-...) to determine the course of action at this level, 3) Take corrective action, and 4) Do RFI/recertification.
Status: OPEN
Action Item 07D-12: Mark K. to submit formal response to NESCOM on SIMICA.
Status: OPEN
Action Item 07D-13: John S. to complete the information model on MAI and send to Darryl B.
Status: OPEN
Action Item 07D-14: Darryl B. to derive an XML schema from the information model and distribute to the subcommittee for review as an alternative to the emerging schema.
Status: OPEN
Issue 01C-1: Testability metrics based on maintenance philosophy, such as Fault Resolution, can provide a means of validating predictive measures. At this point, the information models used to support definition of metrics in P1522 are insufficient to address maintenance philosophy. Need to add a link to the SIMICA information model to reference P1522 and update P1522 to specify both predictive and actual measures. Then need to emphasize the role of MAI in collecting data based on maintenance practice. Still need something to make sure the predictive measures in P1522 reflect those maintenance practices. All of this is contingent upon P1522 surviving.
Status: OPEN Low Priority.
Issue 06C-1: IEEE Std 1522 is not currently being used. Need to examine reasons for this and determine the future of the standard. Some possibilities to examine include: Does it a need management component (ala MIL HDBK 2165)? Are metrics too inaccessible due to tie to 1232? Is it simply a publicity/perception issue? Is there resistance to objective accountability? Discuss with program managers (Russell Shannon—NAVAIR).
Status: OPEN High Priority
Issue 07B-1: The current order constraint in 1232-2002 is difficult to understand and, therefore, difficult to use. The DMC decided to “minimalize” the order constraint to focus only on preconditions and added actions to the model. It is recognized that this minimalist construct is at best suboptimal and possibly “broken.” Unfortunately, timing prevents a new construct being included in the model, and the DMC felt something needed to be there to address ordering. For the next revision, a more expressive and usable order constraint facility needs to be incorporated into the model, replacing the current minimalist construct. One proposal on hand is Log #451.
Status: OPEN Medium Priority
Issue 07C-1: Need to perform a trade study to determine what new services are actually required. This is essential for establishing a usable scope for the service specification. The focus here is for the next revision of the standard.
Status: OPEN Low Priority
Issue 07D-1: These standards (especially AI-ESTATE) are difficult to understand due to the large number of options available to an implementer. It is really important to provide some kind of guidance to the implementer. The hope is that a User's Guide can be put together once the revision has cleared its next ballot.
Status: OPEN Medium Priority
#464 P1232 Action Item Spreadsheet (M. Harris, 9/15/07)
#465 Presentation on P1232 Services (A. Helton, 9/15/07)
#466 Three slides on different topics (D. Busch, 9/15/07)
Call to Order
Approval of Agenda
Reports
Chair's report
Secretary's report
Liaison Reports (CS, I&M, AES)
Brief presentations
Joint meetings as necessary with all working groups
PAR for New Recommended Practice for XML/EXPRESS Instance Document Validation
Finalize AI-ESTATE
Document review
Prepare for ballot
SIMICA Discussions
Document review
Prepare for ballot
MAI Discussions
Document review
Prepare for ballot
P1522 Re-organization
Future of document
Final Discussions on All Topics
Review Old Action Items
Review New Action Items
Set Time and Location of 08-B Meeting
Set Agenda for 08-B Meeting
Adjourn