Every month or so I receive questions about using NIEM in projects.  The questions typically have the same theme, so I thought I would write up a quick post summarizing the questions I get most often and some answers to get you started.

Should I use NIEM in my project?

Do you need a single, canonical data model for exchanging data between systems?  Do you have control of the systems you are integrating?  Do you have an existing data model used within your systems?  Is NIEM a requirement for your project/grant/contract?

If you answer ‘Yes’ to any of these questions then you may consider using NIEM.  NIEM is best used where it will have the most benefit – describing exchanges of information between organizations & systems, harmonizing the language we use to talk to each other (i.e., Organization instead of Agency, Sur Name instead of Last Name), and defining requirements at the data exchange level.  NIEM is not a one-size-fits-all tool and you will not get maximum ROI unless you have a strong use case for it and implement it properly.

Should I use NIEM for my database schema?

The short answer is probably not.

NIEM is an Xml data model and it’s best use is describing the data elements exchanged between systems.  If you need to send data from System X to System Y then NIEM is a good candidate for doing this.  You can define the elements you need to exchange and then build a NIEM IEPD to define the exchange.  Using NIEM as a database schema does not always yield the best results.  In most cases you are better off storing the data in an optimized way for your database platform and using adapters to translate data from the DB into NIEM.

How do I add new fields to NIEM?

In response to this question I would pose a different one – why do you need to add the fields?  Can you derive them from other fields in the exchange?  In most cases the 80% NIEM has built in will get you what you want.  Fields like row-level timestamps or system specific ones may not be necessary and I would tactfully question those.  If you find that you must add a field the best route to take is to define an extension schema in a custom namespace and add the fields there.  Try to derive from base NIEM fields. For example, if you need to add a field to OrganizationType then derive your new type from OrganizationType and add the necessary elements.

Avoid adding the field and not specifying it in the schema properly.  The pitfalls of doing so may not happen immediately but eventually one will and you’ll thank me for warning you.

I would question why you need to add fields as long as possible without delaying your implementation and deployment.  In most cases you really don’t need the fields.

Can I use [Name_of_IEPD] for my project?

It depends.  Does it have what you need?  Are you ok reusing someone else’s work (one of the benefits of NIEM!), then yes.  Sometimes existing IEPDs will be a good fit and get you the 80% or more.  Other times the perspective may be vastly different from yours.  You can certainly propose the use of an existing IEPD and have your business analysts and other technical staff review to see if it is a good fit.

The key to success with NIEM is that it brings together the business and technical teams involved in the exchange. If a particular IEPD is not able to bridge those gaps you may need to create your own.  As NIEM adoption grows, more IEPDs are becoming available and many of them are coming from national groups that are looking at how things are done across the country to find the best 80% that fits most cases.

Getting Started with NIEM – Quick Tips

  • Build a dictionary of the data you have or would like to have
  • Search IEPDs to find one that matches your needs
  • Map your data elements to the elements in the IEPD
  • Store the data in a manner that makes sense for your database platform
  • Translate your data from its source into NIEM and vice-versa
  • Shoot for the 80% because in most cases that is what is really needed

More information about NIEM

  • NIEM.gov – official NIEM Site
  • LEXS.gov – DOJ Logical Entity eXchange IEPDs

For those of you working in the .NET Space check out my previous articles on NIEM + .Net