Extend the end: Overview

The problem

There are situations where almost everything fits in a standard Johnny.Decimal system. But a few items either break the 'no more than 100 IDs' rule, or need to be repeated in some way.

These are minor extensions to your system that don't require the more complex expand-an-area solution.

Example: Chickens

You're using the Life Admin System and have three chickens.

The ID 11.63 Veterinary care might get quite busy. You want a way to track each chicken's visits and treatment plans.

Example: A repeated task within a larger project

We had to install cabling in 13 data centres. But there was already a complete ID allocated to cabling: 72.02.

I could have used a new ID for each data centre. But this didn't match the system's overall pattern and it wouldn't have been memorable. Plus I wanted a unique reference for each data centre's cabling for things like our project schedule.

The solution

Add a + to the end of the ID, then give the new item a unique title. We refer to this as AC.ID+. This is a new entry in your JDex.

Example: Chickens

If we want to track visits to the vet for each of our chickens, extend the end of 11.63 Veterinary care for each of them.

Now you have three new IDs: 11.63+ Belinda, 11.63+ Marie, and 11.63+ Wendy. Each entry is a child ID of the parent ID 11.63.

Example: A repeated task within a larger project

To create IDs for each of the 13 data centres, I used an existing code for that location. The final IDs looked like 72.02+ X01, where X01 was a particular data centre. (I could have used the name of the data centre, but these codes already existed and were shorter.)

FAQs

What am I extending/gaining?

This scheme extends specific IDs by an arbitrary number of child IDs.

How does this affect my IDs?

Your IDs are extended at the end.

How does this affect my JDex?

Each extended entry is a new ID in your JDex.

Can I use this with multiple systems?

Yes. You may extend the end of a SYS.AC.ID system.

Can I use this with expand an area?

No. For an expanded area, extending the end no longer makes sense because you're not using standard AC.ID.

When should I use/not use this?

You should use this in limited situations, in specific categories or IDs.

If you find yourself extending the end too frequently within a system, question its design. You might need to split it into multiple systems. Or you might need to expand an area of the system.