[Moims-dai] [EXTERNAL] RE: CESG conditions on your OAIS Reference Model, CCSDS 650.0-P-2.0

Shames, Peter M (US 312B) peter.m.shames at jpl.nasa.gov
Wed Aug 26 23:34:26 UTC 2020

Dear David, et al,

In general, while I could accept what you propose I would do it rather reluctantly, and for the following reasons:

  1.  In Wikipedia, that font of all knowledge, system, in information and computer science, is define like this:  "system is a hardware system, software system<https://en.wikipedia.org/wiki/Software_system>, or combination, which has components<https://en.wikipedia.org/wiki/Component_(UML)> as its structure and observable inter-process communications<https://en.wikipedia.org/wiki/Inter-process_communication> as its behavior."
  2.  In the CCSDS glossary, that font of our corporate knowledge, system is defined like this: (CCSDS 311.0-M-1) " A set of elements (people, products [hardware and software], facilities, equipment, material, and processes [automated as well as manual procedures]) that are related and whose behavior satisfies customer and/or operational needs".
  3.  Or like this: (CCSDS 910.2-G-1) " A set of one or more computers, the associated software, peripherals, terminals, human operators, physical processes, information transfer means, etc., that forms an autonomous whole capable of performing information processing and/or information transfer."

It is only these OAIS definitions that stray so far from the norm as to attempt to define this particular kind of "system" as being first and foremost about "organizations", as in the original definition, or now, about "policies, procedures, hardware, software, and information."  Systems are systems.  Policies are organizational guidance about how organizations carry out their tasks.  Procedures are instructions about the steps organizations are to follow in carrying out their tasks.  Neither of these are the primary elements of a system, they are strictly ancillary to the use of the system, but useful to the organization.  Likewise information, for that matter.  Systems may store, transfer, and manipulate information, but they are not that information.

Policy (Wikpedia):  A policy is a deliberate<https://en.wikipedia.org/wiki/Deliberation> system of principles<https://en.wikipedia.org/wiki/Principle> to guide decisions and achieve rational outcomes. A policy is a statement of intent, and is implemented as a procedure or protocol. Policies are generally adopted by a governance<https://en.wikipedia.org/wiki/Governance> body within an organization.

Procedure (Wikipedia):   a set of step-by-step instructions compiled by an organization<https://en.wikipedia.org/wiki/Organization> to help workers carry out complex routine operations.

As an instance of a particular kind of SYSTEM, please adopt a straightforward definition of OAIS that does not convolve these other, separate, terms into the definition nor make them the prominent features of the definition.

It's a quibble, but the addition of that phrase "but is not limited to" seems vague and to add no value.  It's rather like sticking ", etc" at the end of a sentence when you cannot summon up another concrete item to add to a list.  But in fact, placed as it is, it seems to take away meaning from the very concrete definition that should follow it.  Please remove it.

I do not have any issue with the use of "put in place" (or "acquired", or "employed") nor the reference to "staff", in the last sentence.

Is it safe to assume that the other changes I proposed have been adopted as proposed or are there changes to these as well?  Your note was unclear.

Thanks, Peter

From: David Giaretta <david at giaretta.org>
Date: Wednesday, August 26, 2020 at 4:22 AM
To: Peter Shames <peter.m.shames at jpl.nasa.gov>
Cc: 'MOIMS-Data Archive Interoperability' <moims-dai at mailman.ccsds.org>
Subject: RE: [Moims-dai] [EXTERNAL] RE: CESG conditions on your OAIS Reference Model, CCSDS 650.0-P-2.0

Dear Peter

The DAI WG reached consensus at yesterday’s meeting to accept your proposals but with a few changes to your proposed definition of OAIS Archive which we think is a bit clearer.

The following shows our changes, with your text as the basis. A few words of your text have been deleted (double strikeout) and additional words inserted (red text).

Some points to explain the changes:

1)      Add “policies” and “information”

2)      To make it clear that the Archive organisation does not have to develop the system itself we use the words “put in place”

3)      In order to clean up the Glossary definition we move the the reference to the section which specifies the mandatory responsibilities to a NOTE.

Open Archival Information System (OAIS): An Archive system consistsing of, but is not limited to, policies, procedures, hardware, software, and information. procedures The Archive system is developed put in place and operated by an organization and its staff.  The organization has accepted the responsibility to preserve information and make it available for a Designated Community. The organisation may be part of a larger organisation. The system An OAIS Archive meets a set of mandatory responsibilities, as defined in section 4, that allows an OAIS Archive to be distinguished from other uses of the term ‘archive’. The term ‘Open’ in OAIS is used to imply that this Recommended Practice and future related Recommended Practices and standards are developed in open forums, and it does not imply that access to the Archive is unrestricted.
NOTE -  The set of mandatory responsibilities an OAIS Archive must perform are defined in section 3.2

I hope you concur with this. We can then go forward with this improved version of OAIS. Once again I want to thank you for suggesting many improvements.



From: MOIMS-DAI <moims-dai-bounces at mailman.ccsds.org> On Behalf Of Shames, Peter M (US 312B) via MOIMS-DAI
Sent: 18 August 2020 18:56
To: david at giaretta.org
Cc: Shames, Peter M (US 312B) <peter.m.shames at jpl.nasa.gov>; MOIMS-DAI List <moims-dai at mailman.ccsds.org>
Subject: Re: [Moims-dai] [EXTERNAL] RE: CESG conditions on your OAIS Reference Model, CCSDS 650.0-P-2.0

Dear David, et al,

I'd like to thank you and your team for taking my suggestions seriously and for working diligently to improve the clarity of the document.  I am really glad that you took this opportunity to make these long overdue changes.  I suspect that your community will also appreciate the changes.

I have read the document (a quick skim this time), and find that I agree with all of the changes that you have made.  The added clarity in use of terms and diagrams helps a lot.  I did find a few relatively minor items that I still wish to ask that you fix.  Instead of doing the usual "change this to that" PID format I just made the proposed changes directly in the text, which I have attached with Track Changes turned on.  For transparency, I will tell you where to look:

Sec 1.1: fixed the definition of an OAIS to align with the usual notion of what a "system" is:

An OAIS is an Archive system consisting of hardware, software, and procedures developed and operated by an organization.  The organization has accepted the responsibility to preserve information and make it available for a Designated Community. The organization may be part of a larger organization.

Made the same change in sec 1.6.2 Terminology.

In other sections and sub-sections I added a clarifying sentences in the intro paragraphs, of the general form: "This sub-section (or this entire section) is non-normative.".  I am concerned that without this sort of clarity the mix of normative and non-normative materials in various sections can cause confusion.  I did not want it to be too intrusive, but I think we must be clear.

To take the "sting" out of this, in some sections I added an explanatory sentence, like this one in Sec 4.2:

This entire subsection is informative, but provides useful abstractions for understanding how an OAIS might be designed.

I hope that you and your team can accept these changes.  If the answer is yes you have my concurrence to go forward.

Thanks, Peter

From: David Giaretta <david at giaretta.org<mailto:david at giaretta.org>>
Date: Tuesday, August 18, 2020 at 9:07 AM
To: Peter Shames <peter.m.shames at jpl.nasa.gov<mailto:peter.m.shames at jpl.nasa.gov>>
Cc: MOIMS-DAI List <moims-dai at mailman.ccsds.org<mailto:moims-dai at mailman.ccsds.org>>
Subject: Re: [Moims-dai] [EXTERNAL] RE: CESG conditions on your OAIS Reference Model, CCSDS 650.0-P-2.0

Dear Peter

Steve Hughes provided us with feedback following your discussion with him. As a result we have taken an in-depth look at the conformance sections, the definitions and discussion of Representation Information, and in particular “Semantic Information”, and the discussion of Representation Information Networks. I believe we have made significant improvements to OAIS as a result. Some of the  text dates back to the original version of OAIS; it is only thanks to your insistence that we were forced to recognize a number of weaknesses and sources of confusion for readers.

The updated document is available at https://cwe.ccsds.org/moims/docs/MOIMS-DAI/Draft%20Documents/OAIS%20v3/650x0020_CESG_Aproval_Mod-20200818.doc?Web=0<https://urldefense.us/v3/__https:/cwe.ccsds.org/moims/docs/MOIMS-DAI/Draft*20Documents/OAIS*20v3/650x0020_CESG_Aproval_Mod-20200818.doc?Web=0__;JSU!!PvBDto6Hs4WbVuu7!Z6HocMIOLyix828rKmjcw8oXm4kvxDc7FslUfK9mFl4AgzgYOB_8YzJbr7ELtVAvJ4ZPi7qM$>

A short list of the changes are:
-          The conformance section 1.4 has been clarified as you suggested and the individual sections are clearly marked as “normative”
-          We checked the use of shall/must. One instance of “must” was missing from a section marked as normative. We found we did have some uses of “must” in informative sections, which we re-phrased.
-          Changed the name of Semantic Information to “Semantic Representation Information” to avoid confusion with Semantic networks etc.  The definition has been clarified to
o   “Semantic Representation Information: The Representation Information that further describes the meaning of the Data Object, and its parts or elements, beyond that provided by the Structure Representation Information.”
-          There is a similar change for Structure Information to “Structure Representation Information”, which is now defined as
o   “Structure Representation Information: The Representation Information that imparts information about the arrangement of and the organization of the parts or elements of the Data Object”
-          The explanation of Representation Information Networks has been updated, with some new diagrams which we hope make the concept very clear.

We hope that clears the way for progressing OAIS to the next stage.



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