Ability to override analysis in a derived template

Roger, We purposefully build analytics such that you can turn off analyses from templates at the instance level and you can also add analyses to elements from templates. We did this because history has shown that overriding templates cause management headaches later on since no one knows exactly what or why something was done and it gets very messy really fast. In your case, is it OK if you were to turn off the analyses from template that you don't want/need and then simply add new ones at the instance level?

In response to Stephen Kwan, "Roger, We purposefully build analytics s..." Hmm, i don't really see why this would become more or less messy that e.g. the excludes and overrides we have at attributes. I build my template inheritance from superset to subset or vice versa. But in either way, you need to exclude attributes or add attributes in a derived template to remove or add functionality. How should i match the analytics to that? I can't really think of another way than either overriding or excluding an analysis. What we want to achieve is that by instantiating the element, all related business logic, PI Points, etc. are created automatically. When we need to copy-paste analytics from some 'copy template' into the instance that would defeat the entire purpose of templates and inheritance.   PS: i stumbled on the exclude feedback item closely linked to this one: Exclude analysis function – Customer Feedback for OSIsoft & the PI System PPS: it is kind of funny you need to add attributes to exclude them in de derived template

The way I read your original post was that you wanted to override the templated analyses. This, IMHO, would create a lot of confusion because someone later one would come along and see that the overridden analysis is different than the template. There's a good chance that this person would not know why there's an analysis from template, yet it's not the same as the template. That's what I was trying to convey.

In response to Stephen Kwan, "The way I read your original post was th..." So you upvoted? I think that will fit in the 2017R2 release this fall...

We currently provide the ability for you to disable the templated analysis and add a new one. Is that sufficient? If so, can you please elaborate?

The following inheritance semantic features from OOP languages, such as C++ and C## are required: a) Overriding an inherited analysis in the derived template by using the same name as in the parent template. This feature is already available. b) Ability to call the parent implementation (which avoids copying the code), followed by the overriding code in the overriding implementation. This may be enabled either by a property check box, or some additional analysis syntax. USE CASE (simplified): parent analysis calculates a KPI = f(a,b). Derived analysis extends the calculation, KPI = f(a,b)*c. The KPI is (obviously) written to the same PI Point DR. A workaround would be to combine analysis and formula, where the parent implements a formula that calculates f(a,b)*c for a trivial value of c. The derived template overrides c. However, this is inelegant and less efficient during high frequency calls to the formula DR (such as in BI use cases with PI SQL queries over long time ranges). Also, the formula approach only applies to simple extensions that may be implemented in formulas.

Another feature required of overridden analyses is the ability to handle excluded attributes, which are excluded by overriding in the derived template. This ability is wider required and the lack thereof a right pain at present. (Apparently, promised for AF 2018).

I am surprised that this is declined. This is a feature that currently exists and works. In a derived template, you can create an analysis template with the same name as an analysis in the base element (that appears greyed out in the derived template). In an element created from that derived template, the analysis from the derived template will be used, and not the analysis from the base element template. Granted, you can't edit the analysis from the base element, but you can copy & paste and change it if needed.