Welcome to this video on: "See the light: Easy wins to improve your asset framework
experience". We have applied a whole load of best practices in this class so far,
going back to the beginning we looked at some of our standard asset framework best
practices and at the moment we are currently going through our analysis best practices.
On the analysis side the first one we mentioned was splitting up a calculation into multiple steps
and trying to reduce the number of calls for data to the data archive; the second best practice we
spoke about was just trying to apply some common sense to your scheduling. It is very easy to leave
a periodic one-minute schedule when testing your environments, so if you are experiencing high
resources it's often the first place you will find problems in the configuration of your analyses.
Now we are going to start looking at the roll-up analysis. So in our case the chief process
engineer wants to monitor the average availability of all of our FFS units and one of his colleagues
suggested that he used the formula data reference, because it's very easy to set up and it evaluates
on the fly so there is no data storage or no PI tags used. In order to create that formula he
went into PI System Explorer, created a variable called average availability and then set the data
reference to formula. Now in the settings field, each of the availability attributes from each of
the form fill and seal machines was provided with a parameter A to F. Now important to note here
that you can only have 26 parameters, because our parameters are issued A to Z. Our equation is very
simple just sum all the availabilities divided by six and you will have a availability value.
Now that is one way of calculating the average availability using the formula. There is another
way when the engineer got back from some PI asset framework training he learned that there were
roll-ups that you could configure. So if we have a look at packaging and go to the analysis tab,
you can see we have a roll-up calculation, very similar in the beginning to the expression
analysis where we give it a name, specify the analysis type, only the configuration
is different. For an expression analysis you go in and you type in your formula, you have statement,
your steam calc so whatever you want to do and you output it to a variable. Now with a
roll-up analysis what you do is you roll up attributes from other aspects of the asset
itself but much more common is to roll up attributes from the child assets.
So if we have a look at this packaging has six child assets there are FFS 1 to 6 and what we
want to do is roll up the availability and calculate the average of that attribute. So
by hitting evaluate I can see that my average availability across all of my child assets is
80 point three eight four. I've got my period scheduling configured so in this case we're
doing it every minute and what's gonna happen now is that every minute the system is going to
take all of the availability values from my six assets, calculate the average and
write it out to the variable called average availability - roll up I believe it's called.
So if we go to attributes this average availability - roll up. Now you'll see
these are not exactly the same but they are close enough to the decimal point;
it just depends on when the value is triggered because remember we're not triggering them at
exactly the same time. The major benefit of using the roll-up analysis is that I could change the
number of child assets that I have and let's say I no longer need form fill and seal machine unit
number one. I'll go ahead and delete it. I'll say okay and now when I go to packaging, if I hit will
need to check in for that change to be logged in. Yeah if I hit refresh we're going to run into this
issue where the formula reference is trying to reference FFS 0-1 availability that asset no
longer exists so the system is unable to do the calculation successfully. In order to fix this
what I'd have to do is go to my settings, delete that in the template and then divide by five.
Much easier to let the analysis run in the background because it automatically knows
how to handle an increase or a decrease in the number of child assets and our roll-up
calculation is going to be just as accurate now as it was before. Cool that's the last
best practice we're going to go through in our videos, there are a few more for you
to read through in the remainder of the course, I definitely wouldn't skip them
they're just slightly smaller and easier to digest as an exercise that you read through.
Now once you've gone through those we'll give a a breakdown of all the issues that were solved,
what best practices were applied to fix those problems and if you feel like there's more
research you'd like to go through I definitely suggest heading over to either PI Square or
learning.osisoft.com and taking advantage of the resources that are available for you there.