Page 1 of 1

When is a "hierarchy" not a hierarchy

Posted: Wed Oct 03, 2018 12:36 pm
by lotsaram
OK so this has been bothering me for a while.

When discussing dimension structure (particularly with other “oldschoolers”) the term hierarchy is often (mis)-used to describe internal ancestor-grandparent-parent-child relationships as opposed to the "textbook definition" of a dimension hierarchy in the context of Planning Analytics.

Dimensions having named hierarchies, and elements and their structure belonging to the hierarchies and not to dimensions is a new paradigm for most of us but the point that the term “hierarchy” now has a very specific meaning and we should use it correctly, otherwise it is confusing and we have to second guess what is actually meant.

Incidentally there's a good blog post on this topic here. I like the idea of using the term "rollup" or "rollup structure" in place of "hierarchy" to describe internal element relationship structure and basically swapping out "hierarchy" for where we would have said "dimension" in the past in pre-Planning Analytics days.

Now I may be a pedant, but I'm not that much of a pedant that I would ever insist that a business user should abide by the terminology described in the article. After all why would a business user even care? But a TM1 / Planning Analytics consultant as a subject matter expert should care. It's our job as technical experts to communicate clearly and unambiguously and using the term hierarchy incorrectly is a habit we should kick, even if it takes a little bit of effort.

Now I'll admin that this topic doesn't posses the theoretical gravitas or passions of the "single continuous vs. multiple discrete time dimensions" discussion. But anyone want to pass the popcorn and nachos?

Re: When is a "hierarchy" not a hierarchy

Posted: Wed Oct 03, 2018 2:01 pm
by PavoGa
I'm with you on this one. Pretty much insist our teams adopt and use specific terminology to describe discrete items, sets of items or objects. We adopted rollup to describe what we use to call hierarchies as you described.

What we have found is a need to manage hierarchies, in terms of historical vs the current default hierarchies. We have gone the path of a primary name, a suffix and a numbered prefix and use the caption to describe.

Re: When is a "hierarchy" not a hierarchy

Posted: Wed Oct 03, 2018 9:51 pm
by macsir
I agree. It just takes time to get used to it.
Wherever we were used to saying dimension simply replace with “hierarchy“. Hierarchies contain rollups. In fact hierarchies are now the containers for elements, rollups, subsets and attributes (not dimensions, that was back then, we need to get to the now).
The term dimension should only be used when talking about cube structure. Dimensions in PA are merely a container for hierarchies.

Re: When is a "hierarchy" not a hierarchy

Posted: Thu Oct 04, 2018 8:43 am
by garry cook
Could not agree more, a difficult but important habit to break.

Re: When is a "hierarchy" not a hierarchy

Posted: Sun Oct 07, 2018 1:17 am
by Alan Kirk
Sigh, I'm still trying to get my users to stop saying "subsets" when they mean"consolidations" and vice versa...

To that end, I much prefer the term "consolidation" to "rollup". Why? Because for the foreseeable future there will continue to be a little button named "Rollup" which has a distinctly different functionality to an actual "everyone with security access can see it and use it" consolidation.

The other thing to bear in mind is that while it is good practice to use the right terminology with other professional TM1 admins and developers, there is the little problem of explaining this to end users who have read the TM1 User Guide (OK, "seen and dipped into"; nobody actually READS the thing) , where the definition of both hierarchies and dimensions are distinctly "old school".

Wait, what? Oh, Perspectives will be replaced by PAW and PAX, so that documentation and its screenshots of Excel 2003 will go away? Yeah, some millennium when the ease of installation and reliability of PAX comes even remotely close to that of Perspectives, maybe. But in the meantime those who hang on to 10.2.2 unto grim death or who go to PA2 sans the PAW / Pax installation train wreck will still be seeing said antiquated documentation and will be more than a tad confused when devs / admins who are using the New Authorised terminology speak to them.

Re: When is a "hierarchy" not a hierarchy

Posted: Mon Oct 08, 2018 5:38 pm
by ndivine
Dimension is still needed, not everything is a hierarchy. It's possible to have dimensions and no hierarchies, but you can't have hierarchies without dimensions.

Re: When is a "hierarchy" not a hierarchy

Posted: Tue Oct 09, 2018 5:50 am
by lotsaram
ndivine wrote: Mon Oct 08, 2018 5:38 pm Dimension is still needed, not everything is a hierarchy. It's possible to have dimensions and no hierarchies, but you can't have hierarchies without dimensions.
This is kinda the point. No it's not like that. In Planing Analytics all dimensions have hierarchies. You can't in fact have a dimension without a hierarchy. Many dimensions may have only ONE hierarchy and the hierarchy may have the same name as the dimension, but it's still a hierarchy all the same

Re: When is a "hierarchy" not a hierarchy

Posted: Tue Oct 09, 2018 4:50 pm
by ndivine
lotsaram wrote: Tue Oct 09, 2018 5:50 am
ndivine wrote: Mon Oct 08, 2018 5:38 pm Dimension is still needed, not everything is a hierarchy. It's possible to have dimensions and no hierarchies, but you can't have hierarchies without dimensions.
This is kinda the point. No it's not like that. In Planing Analytics all dimensions have hierarchies. You can't in fact have a dimension without a hierarchy. Many dimensions may have only ONE hierarchy and the hierarchy may have the same name as the dimension, but it's still a hierarchy all the same
Yes, I guess I was thinking old UI's where the same-named hierarchy is pretty well hidden. Part of my point was the necessity of the ongoing use of dimension as a word/term; it's usage shouldn't be thrown out because it is still something uniquely different from a hierarchy.

I have clients that have upgraded to the latest versions of PA, but were not interested in using PAX/PAW for the time being, so I've stuck to old/standard terminology with them.

To your larger point, yes, I think consultants and experts should communicate as clearly as possible using correct terms (especially with each other), but when communicating with business users be flexible according to the terminology that is understandable to them while also guiding them toward the correct terminology.

Re: When is a "hierarchy" not a hierarchy

Posted: Mon Oct 15, 2018 3:02 pm
by Elessar
Hi,

I disagree with the term "Consolidation", because this will lead to disambiguation with financial consolidation

Re: When is a "hierarchy" not a hierarchy

Posted: Tue Oct 16, 2018 9:32 am
by lotsaram
Alan Kirk wrote: Sun Oct 07, 2018 1:17 am To that end, I much prefer the term "consolidation" to "rollup". Why? Because for the foreseeable future there will continue to be a little button named "Rollup" which has a distinctly different functionality to an actual "everyone with security access can see it and use it" consolidation.
Elessar wrote: Mon Oct 15, 2018 3:02 pm I disagree with the term "Consolidation", because this will lead to disambiguation with financial consolidation
I also disagree with the term "Consolidation" but not because of statutory financial consolidation. I think that is a pretty well defined term with a very specific meaning and context. Rather I disagree because "a consolidation" in TM1 already has a defined meaning referring to a (single) consolidated element that is a non-leaf element which itself has children. This is what the "C" stands for in the element type (and the ancient XDI dimension editor). I think this is therefore more rather than less ambiguous versus "Rollup".

Yes in the old subset editor there is a "Rollup" button but this refers to the action the user is performing; they are rolling up elements to form a new consolidation (or rollup). Maybe in both cases "Rollup Tree" OR "Consolidation Tree" is more descriptive and more accurate, ... but then also less simple as it requires 2 words rather than one.

Anyways, seems this topic was a less controversial than anticipated. I'm a little disappointed to be honest.

Re: When is a "hierarchy" not a hierarchy

Posted: Tue Oct 16, 2018 10:10 am
by Elessar
I think it would be a good topic for the new monthly poll :)