How many Equipment Categories? A ramble

Here in Australia, the truly excellent #MasteringSAP Enterprise Asset Management conference has just concluded. Held on the Gold Coast in sunny Queensland Australia, the weather was warm, the breeze refreshing – and the conversations were flowing.

At the end of a day, over a refreshing beverage, a thoughtful conference delegate boldly interrupts the flow and quietly asks – “What is the use of an Equipment Category? How many can we have? How many should we have?”  You can picture the scene – the banter stops, glasses are dropped, voices go quiet and even the band stops playing.

This is the kind of question that really forces us to stop and have a think. How many? What do they even do? What use are they? All great questions to ask at an EAM conference.

Before reading on, why don’t you pause for a moment and ponder how you might answer those questions.

So what were some of the responses? Not surprisingly, there were a variety of answers.

The number one answer was – yes you guessed it – “It depends”. Yeah OK I hear the words, I even understand the words, but the answer begs the question – depends on what?

Another frequently offered answer (FOA) was “As many as you need – but not too many”. Again not really helpful. How many does one need?

These answers triggered more questions in my mind – leading me to approach the questions from another angle. “How few equipment categories can we have?” and “Is there a limit on the number of categories?” Whilst neither question leads us to answer the original questions absolutely, answers to these questions might be of some help in getting closer to an answer. So let’s start exploring.

“Is there a limit on the number of equipment categories?”

I believe there is, well at least in the ECC system that I’m presently sitting in front of.

The equipment category data element – EQTYP – is defined with a domain – EQTYP. The domain is associated with character string type holding 1 character and the character is case insensitive. Armed with these details, I think we approximate an upper bound.

Assuming 26 English letters + 10 Arabic Numerals, that gives us 36 Equipment Categories. If we are open to a few of the “special characters”, we might be open to another 10 or so. Other languages might squeeze a few more. Whatever these equipment categories do, we have an upper limit of around 25 – 50 of them. Not hundreds or thousands.

“Is there a minimum number of equipment categories?”

Our intuition would suggest we might need at least one if we are going to be dealing with equipment in the system. This isn’t dissonant with the documentation of equipment category, which paraphrased, describes the equipment category as a means of distinguishing equipment by their use. If I have no diversity of use, even without knowing what diversity of use means, I’d have at least one group. But how few must I have? Like the maximum limit, is there a system or design constraint that might necessitate more than one equipment category?

To explore that question, we need to look at how the equipment category is defined and then used in the system. The equipment category domain EQTYP is defined with a value table. The value table functions as a (check) table of permitted values. In the case of equipment types, the value table is T370T – Equipment Categories. Here we find not only a set of permitted equipment categories, but also we see that the equipment categories have attributes. And so begins our journey exploring how many are actually needed.

An abstract answer, based on data model alone, suggest one needs at least as many equipment categories as the number of distinct sets of equipment category attributes. OK – that is a bit dry, so what are some attributes of equipment category and what do they do?

Let’s take one very basic attribute. Number range. If you want a group of equipment to have a different range of numbers from another group of equipment, you need to define two equipment categories. What about if you want some equipment to be installable in a functional location and some not? Then you need to define two equipment categories – one installable and one not. And if you want some of the installable equipment to also have a different range of numbers from other installable equipment – well you get the idea – another equipment category.

A quick glance of the attributes gives us a flavour of the various things to consider. Do I need to distinguish linear equipment from non-linear? Are some equipment relevant to financial asset integration and some not? Are some equipment used in a sales process? Are some equipment serialised and stored in inventory? Should some equipment be configurable? Are some equipment involved in IS-Utility processes? Do some equipment have different processing states, leading to different status profile? These are just a few of the attributes that define how the equipment of an equipment category can behave.

Careful exploration and decision making around how equipment can behave and be processed in your system determines the number of distinct sets of these attributes. This in turn defines the minimum number of required equipment categories. However this is just a minimum.

Other system constraints elsewhere in the system might well trigger the need for another equipment category even when the category attributes in T370T are identical. An example is the behaviour of serialised equipment which depends upon assignment of equipment category to serial management profile in table T377P. If you want equipment to have different serialisation behaviour then different equipment categories are required so they can be assigned to different serial management profiles. It might also be you want different screen layouts based upon equipment category, but I ask Do we really need different SAPGUI screen layouts in a Fiori world?

For a business that perhaps has IS-U devices, some fleet equipment, equipment as tools, has business processes using serialised equipment and some linear equipment, then number of equipment categories that need to be defined is still likely to be less than 10.

For a business without such a diversity of processing, the number you need may well be lower.

To determine how many you need, perhaps it is best to start with the SAP defined equipment categories – each of which represents a processing behaviour – and really carefully ask – why do I need more?

There is truly value in keeping things as simple as possible and as complex as necessary.

So now looping back now to the original questions:

Q: What is the use of an Equipment Category?
A: An equipment category defines the system behaviour and processing options for a set of equipment.
Q: How many can we have?
A: Somewhere between 4 to 5 to 40, 50 at the very maximum.
Q: How many should we have?
A: As few as necessary. If you are above 10 – start doing a sanity check.

To the thoughtful delegate who asked the question, thank you! I hope next time the topic of equipment categories arises, we all can discuss the question with greater confidence and clarity.

Postscript:

This little article by no means outlines all the interactions and dependencies of equipment category.

This article was written, edited and spell checked using Vim text editor.
:wq