[Moims-mp] Another minor update to MPS Blue Book

[roger.rocketbrain at btinternet.com]

I have uploaded draft G5 of the MPS Blue Book to the Google Drive.  If you
are raising comments on the BB, please do so on this version if possible.
 
This reflects agreement last week in the SM&C WG concerning Short Form Parts
and MO Object Numbers.  This was an issue that I had raised some concern
about previously within our WG, but had been raised as an issue by someone
else in the SM&C WG on the draft MAL v2.0 BB.
 
For those unfamiliar with it, the MAL requires each data structure to be
assigned a Short Form Part (SFP) – a unique number that is used to identify
a data structure when efficiently encoding a message.  In MAL v1 it was
scoped by Area and Service, so the full identification of the data structure
was formed from Area#-Service#-SFP.  This was an issue for MPS as our
information model has data items that are not specific to any one of our
services, so with the exception of Planning Requests and Plans, all other
data structures were defined at Area level.  There was some debate on
whether data structures could be defined at area level, until it was pointed
out that the MO M&C service had data structures defined at area level.
 
With the introduction of MAL Objects, the concern had been raised that there
was no ServiceID within ObjectIdentity and ObjectRef, so clearly the Type of
the object could not be encoded as the SFP.  As a result I had defined
dedicated Object Numbers in the MPS BB – and noted that it would be
desirable to harmonise this with the SFP, but that this was not possible at
present as the ObjectIdentity had no ServiceID element.  The initial
proposal was to add this to the ObjectIdentity – adding yet another field.
 
There was an extended discussion – but to cut to the conclusion:
1.	All Data Structures in an MO standard are to be defined at Area
level – so SFPs must be unique within the Area, not the Service.  Data
structures are no longer specific to Service.
2.	MO Object Numbers are the same as the SFP for the corresponding data
structure (defined as extending MAL::Object).
 
This is a good outcome, as it removes a level of complexity, harmonises the
short form numbers for data structures and objects (in ObjectIdentity and
ObjectRefs), and means that there is no requirement to artificially
associate information model elements to a specific service when they may be
used or referenced by multiple services.
 
As a result I have updated the MPS BB to be consistent with this approach.
The impact is relatively minor, but involves the following changes:
1.	Previously we had assigned SFPs for data structures related to the
Planning Request and Plan data items to the Planning Request Service and
Plan Distribution Service respectively.  They had SFPs starting from 1 which
in the absence of a scoping service would be non-unique.  All other data
structures were defined at Area level, but with SFPs within defined ranges.
This meant I had to define new ranges for Planning Request and Plan data
items.  
- MPS general Data Types had been assigned SFPs in the range 1-100; Planning
Activities 101-200; Planning Events 201-300; and Resources 301-400.  These
cover the majority of MPS data structures and are unchanged from draft G4.  
- Planning Requests are now assigned SFPs in the range 401-500
- Plans are in the range 501-600.  
- Planning Users now require an SFP – as this is the same as its Object
Number this has been assigned the SFP 601.
- The SFP for the MPSSystemConfig object has been changed to 701 (was 401
now within the Planning Request range).
- The SFP range for Functions has been changed to 801-900. (was from 501 now
within the Plan range).
This has been updated in the introductory section on SFPs in §3.1.2
2.	The SFPs in the data structure definition tables have been updated
accordingly in §3.2.5 Planning Requests; §3.2.6 Plans; §3.2.8 MPS System
Config and §3.2.9 Functions
3.	The MO Object Numbers in the table in §3.1.1 have been updated to
make them consistent with the SFP of the corresponding data structure
definition.  As a result, the Object Numbers are now:
101         Activity Definition
102         Activity Instance
201         Event Definition
202         Event Instance
301         Resource
401         Request Definition
402         Request Instance
501         Plan
601         Planning User
701         MPS System Config
4.	In the section on MPS Planning User §3.2.7, a data structure table
has been added to include the definition of its SFP in the standard way.
The text has been updated to note that the data structure can be extend with
system specific information and that it is not used as a data structure in
the MPS services.
 
Cheers,
 
Roger
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