Data Model

*A note before starting. I live in the world of Corporate Real Estate (CRE). So, this article is geared towards that audience but is in no way exclusive of any other area. :) Enjoy!

Continuing down our data path, this week, let us chat about Data Models.

A few years ago I was taking classes to become a software engineer. My direction eventually changed to perusing a degree in data analytics but one thing was common in both degrees, modeling data.

Whether it was outlining a program or designing a database, each started with sketching out what the "thing" being created was made up of and how the pieces connected together.

Planning out you Corporate Space Data is no different.

This is where a Data Model comes into play.

The design process for the Model typically involved three stages, conceptual, logical, and physical.

Conceptual

The below picture, from the Wikipedia entry for a Conceptual model, gives a general idea of what one looks like (hey is that a data dictionary?! :) ) The Conceptual model is the highest-level of the three models and is meant to outline the core "buckets" of information. For example, picture one box for Properties, another for Buildings, another for Floors, and so on.

At this stage, there is no need to get into the weeds. That comes in the next phases.

Logical

After you have worked through the Conceptual model, the next phase is adding more details to all those boxes. The image below comes from the University Consortium for Geographic Information Science GIS&T Body of Knowledge DM-35 - Logical Data Models.

Here we start to see the model shaping up. There are attributes that are associated to the table and lines, or relationships, connecting the boxes. We also see, in parentheses, "PK" and "FK". This stands for Primary Key and Foreign Key. The Primary Key is the unique identifier for that table and the Foreign key is an attribute that is a primary key within another table. For example within a Building there are floors. The floor number can be a foreign key in the Building table and a primary key in the Floor table.

Physical

That last phase is the Physical model. This contains information that is used to actually create a database that the previous phases were representing.

Physical data modeling?involves transforming the logical model from a purely business design to a design optimized to run in a particular environment. (Roth, 2021)

As we can see in the below image, there is a bit more detail. The attributes have formatting (char for character) and character length (20 for max number of value length) representation.

Whew. That was a lot! Are you going to go and design a Corporate Real Estate database now? Probably not, as I hope, one already exists. BUT if you never seen the data model for your system, it may be worth checking out.

One benefit to any of the models is that it is a visual representation. I am a big fan of visualizing complex information and what easier way to do that than with a bunch of boxes connected with lines!

One last application for a conceptual model is visualizing all the different systems and how they are connected. For example, does your CAFM program feed location data to your HR system? What from your HR system feeds your CAFM program? How does Outlook get updated, what feeds that? There are any number of programs and systems that are fed or feed things. Being able to see those connections graphically can make things a lot easier to understand.

And if something like that doesn't exist, create one! You will be amazed at how valuable a "spider-webbed" image of all the connected systems can become!

Thanks for reading. If you have any questions,?do not hesitate?in adding a comment or messaging me. I am always willing to help!

Resources

Nyerges, T. (2017).?Logical Data Models.?The Geographic Information Science & Technology Body of Knowledge?(1st Quarter 2017 Edition), John P. Wilson (ed.). DOI:10.22224/gistbok/2017.1.2

Roth D. Physical Data Modeling. EWSolutions. https://www.ewsolutions.com/physical-data-modeling/. Published May 25, 2021. Accessed March 30, 2022.?