3 thoughts on “What is brown and sticky? The metadata conundrum.

  1. Metadata is data that describes data! The enterprise Logical Data Model is a Metadata Model because it describes the elements and structure of the data required to support the core activities of the enterprise – Business Functions.

    It is a mistake to look to processes for data. Processes do not create data! Business Functions do. A Process simply defines the order in which Business Functions are carried out in response to a specific trigger in order to arrive at a predefined outcome.

    It is the steps in the Process – the Business Functions – that create, transform and use data. Know your Business Functions and you will know your data.

    It is also a mistake to talk about ‘data quality rules’. These are Business Rules that are an embedded part of a Business Function. These should always be defined at the logical, rather that the physical, i.e. they should refer to entities, attributes and relationships, rather than tables and and records. The implementation of these business rules would result in quality data being created.

    Regards
    John

    • Hi John

      Thank you for your comments.

      Of course the definition of metadata is “data bout data”. This is precisely the problem – it is vague and all encompassing which means, frequently, that multiple people talking about this can mean different things creating massive confusion.

      Business processes map and relate business functions – therefore they are a perfectly reasonable place to start!

      Business rules are once again all encompassing – not all business rules impact on data quality. Data quality rules are an accepted subset of business rules that measure the compliance of data to the business need. Once again. in the interests of accuracy I believe that the more precise we are about what we mean the less chance we have of causing confusion.

      That being said, there are many more examples of metadata that can be listed – my list was by no means definitive.

  2. Interesting perspectives but we can’t look at metadata in isolation. In practise metadata only adds value when it describes the underlying data. The proof of the pudding is in the eating. I too see a three tier model but would describe the tiers slightly differently.
    Tier 1.
    Conceptual data model, a high level 50,000 foot view of the enterprise. A bit like a map of the world, useful to orientate an diverse group of people or to check you’ve arrived at the right planet but useless for finding your way home.
    Tier 2.
    Logical data model. Third normal form data model using abstract concepts like party (customer, supplier, person or organisation, employee, employer etc). Excellent way of ensuring you only store data once, dependent on the key, the whole key and nothing but the key. Also a great base for ensuring the organisation can have a single version of the true but, to business folks a third normal form data model is about as interesting as a wiring diagram of their office. Do they care?No,  not till the lights go off and then they will call an electrician, well what would you do? Business people have other objectives, they won’t care what goes on behind the light switch and do not want lessons in reading wiring diagrams thank you very much. What they want are devices that work when you switch them on, computers that give them the right answer, not a lesson in semantics.
    Tier 3.
    This brings us to the Access layer sometimes call the semantic layer. Built on top of the third normal form core the access layer presents the data the way the business likes to see it. For example sales people see a subset of that Party entity as  “customer”, whereas to purchasing another subset of Party is “Vendor”, or “Supplier” depending on their preference. The KPIs can be predefined, by the appropriate business department, and exposed here to.  The access layer is the interface between the abstract third normal form concepts and the real, tangible, objects that business people deal with every day. 
    Now the challenge becomes one of understanding how these tiers map together but that’s a lesser challenge than trying to build a tower of Babel.

    Andy.

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