HOW DO I … USE PI FORMULAS TO CALCULATE PERFORMANCE RESULTS?
SCOPE & STRUCTURE OF THIS HOWDY
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An overview of Covalent formulas
How formulas work
How to setup your PIs to use the formula calculation
Worked examples
Using brackets in formulas
Setting up numerator and denominator columns for percentage and ratio PIs
Jargon that you’ll need to know
Activated
Activated means that the PI value has been entered and
saved, and is cleared to go on the live system; prior to that
the value will show in the value column but will not be used
to calculate the status of the indicator (i.e. whether it is at
red, green or amber).
Thresholds, PIs
In PIs, Red/Amber Thresholds are used to specify the values
at which a performance indicator is deemed to be in the
red, amber or green zone
Navigation for this Howdy
Go to PIs topic in the navigation panel at bottom of screen and select PI List from the sub-options available.
Please note: the topic buttons on your navigation panel may not match with the default layout described
here.
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OVERVIEW OF COVALENT FORMULAS
If desired, Covalent can be set to calculate the PI result from other data held elsewhere in the system. This
other data might be another PI, or it might be a data point (say a numerator in a calculation) or it may be a
constant value type of data point such as say population.
The actual formula used to specify how the PI is calculated is stored in the Formula Tab, as on the screenshot
below.
Some indicators may be specified as “data only” if they are to be used in a Covalent Formula calculation, but
you don’t want to hold the full range of information that you would normally hold for a PI, for example
targets and status icons.
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SETTING UP A FORMULA
Formulas are specified in a similar way to Excel, except that instead of using cell references, here you use the
PI code. Brackets can also be used to separate each part of the formula.
For example, if you first set up two feeder PIs, one with the code POP and name it Population (feeder PI 1)
and another with code CP (feeder PI 2) and name it cost of planning, then the PI cost of planning service per
head of population (primary PI) can be calculated by entering the following formula – CP/POP.
Similarly % of invoices paid within 30 days can be calculated with the formula IP1/IP2*100 where IP1 is
number of invoices paid within 30 days and IP2 is the total number of invoices.
And PI called average number of sick days at corporate level (SKtot) can be calculated using feeder PIs
SK1+SK2+SK3+SK4/4 where each of these is the number of days sickness in individual department, divided
by 4.
Average time for calls for number of divisions could be calculated by using (CallTime_Div01 + CallTime_Div02
+ CallTime_Div03) / (NoCalls_Div01 + NoCalls_Div02 + NoCalls_Div03) where CallTime is the total length for
all calls for that division and NoCalls is the number taken for each division.
As you enter each of the PIs within the Covalent Formula field, the system will accept the code as soon as it
recognises this PI on your site. If you have mathematical symbols within your codes, such as +, -, / and *
then the PI code must be enclosed in double quotes.
Save your PI and the formula field will automatically surround any PIs with quotes and show you the feeder
PIs within the Formula Drivers panel, as shown here:
How the formulas work
First of all you need to create all the “feeder” PIs (or Data points) that will be used in the formula, thus in the
last example above the PIs SK1, SK2, SK3 and SK4 need to be set up first.
Then you specify the formula, as above example, in the formula field of the PI the feeder PIs are feeding into
(primary PI).
And finally you enter the data values into the feeder PIs. When the value for the current time period is
entered and activated for the last feeder PI, then Covalent automatically calculates the result for the primary
PI itself.
Thus for example with the formula for average days sickness at corporate level - SK1+SK2+SK3+SK4/4 – you
might enter the June 2010 value for first department SK1 (say 2), then the June 2010 value for SK2 (say 4),
SK3 (say 4) and SK4 (say 6). Once the SK4 value is activated, then Covalent will calculate the value for SKtot
for June 2010 as 4.
Note: if you are dividing by zero as a result of hour formula the value will show ‘DIV/0’
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How N/A values are handled in formulas
N/A values can be handled by Covalent in two different ways. Which way they are handled is a site-wide
setting, found in the PI tab in Site Setup, as shown here:
The default option is N/A values count as 0 when adding or subtracting, this will set N/A feeder values within
a formula to be treated as a 0 when they are part of an addition or subtraction function.
The second option is If there is any N/A driver data then the result data is always N/A, which will return
any equation containing an N/A value as being N/A, for example 3 + N/A will be represented as N/A
Please note that changing this option will not change historic data in the system; only new values will be
affected by this option.
Tip:
If you have quite a few feeder and formula PIs to setup, then it may be quicker for you to use the import
spreadsheets to setup this information. Add the feeder PIs first in the list then the formula PI and upload
the information.
Data Collection Settings
Once you have created the feeder PIs and entered the formula in the formula field, the last step is to set the
‘Data Collection Settings’ for the primary PI which will use the feeder PI values.
When you tick the checkbox on the Formula tab to say that this is a Formula PI you will get the following
message:
Clicking Create will set any data collection settings that were defined as manual collection to be collected
using the formula, which may be all you need to do, however you may also want to define other data
collection settings that must be done at this point.
To set to ‘formula’ the relevant time period, click on the Collection Settings Tab. In the example below, the
monthly data will come from feeder PIs and will be calculated using a formula, hence the settings:
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If the source is NOT set to use formula, then the PI will appear in the updates screen for manual updating when next
due.
The Target Source in this case is also set to Formula, this means the target data will be calculated from the targets in
the feeder PIs using the same formula.
By default the interval is set to 1, change this if your feeder PIs have interval of something else, not setting this will not
stop the formula from calculating correctly when data is entered to the feeder PIs, but it will enable the short-term
trend arrow to calculate.
By ticking the ‘Allow Edit’ box, this will allow you to edit the final value that Covalent calculates via the formula. If no
tick is placed in this box then editing of the final figure will not be possible.
Important
Note that formulas currently only work going forward – that is for values entered and activated after the
formula has been set up.
You can get the formula to calculate against historic data if you first set up the formula, then press the button
Recalculate Formula Data in the PI window, then all data will be recalculated for this formula.
Also beware of using formulas with PIs that have codes containing mathematical symbols as Covalent will
regard those as part of the formula. For instance, if you used a PI code like L-BA21 in a formula Covalent will
read this as PI coded L minus PI coded BA21
If you do have PIs using this format, enclose your PI in double quotes, i.e. “L-BA21”+”L/BA21”.
Mirroring PIs
It is possible to get Covalent to ‘mirror’ a PI. This is done using the formula function by simply entering the
PI code of the PI you wish to mirror into the formula field.
Example: if you had a PI coded BV99 but wanted this PI to display the results of data entered in a local PI
called SPS21, enter the code SPS21 into the formula field of the BV99 PI and set the data collection settings
source of BV99 to ‘formula’ for the relevant collection period.
Now, when data is entered into PI SPS21, the result will also be shown in PI BV99.
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If you wish to have gauges for both PIs, then set the PIs up the same with same thresholds, target data etc.
If using target profiling against an annual target, then annual targets must be set up and the appropriate
target source set (in the collection settings tab) for both PIs.
It is possible to get Covalent to mirror targets. For instance, if you entered 50 as a target for May 2006 for
BV99, this will enter 50 as a target figure for May 2006 in PI SPS21. This is achieved by clicking on the
Calculated Target checkbox and the formula will calculate the target value in the same way as the actual
value, and in this case mirror those values.
CALCULATING ANNUAL OUTTURN FIGURES
It is possible to use Covalent to produce outturn (end of year) figures for you automatically by applying some
simple settings.
However, when it comes to calculating accurate outturns for percentage PIs (non-accumulative), it is
necessary to use a formula and feeder PIs to obtain an accurate figure (explained later)
Calculating outturn figures for Number PIs
To get Covalent to produce outturn figures for number type PIs requires the setting of some propagation in
the settings tab of the PI.
In the example below, by entering a monthly figure manually, Covalent will calculate the yearly outturn figure
for you, using the month’s figures as a source:
Alternatively, the source could be set to Quarters if this PI was collected quarterly and not monthly. The
setting would look like this:
You then need to specify the type of calculation you wish Covalent to make using the calculation drop down:
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 Use latest activated data – This will use the last activated data on the data tab of the PI for the time
period as specified in the source drop down. For example, if this was a monthly accumulative PI,
where month 12’s figure would be the same as the outturn figure, then you could use this setting.
 Average all Activated data – this will sum all the data for the time period specified as the source,
and calculate an average figure for the outturn. For monthly collection, it will add together and divide
by 12 to get an average, likewise add and divide by 4 for quarters.
 Sum all activated data – This will add up all the activated data for the time period specified as the
source, and use the result as an outturn figure.
Allow Edit tick box
Be sure to place a tick in the Allow Edit box only if you would like to be able to edit the outturn figure that
Covalent calculates.
Calculating outturn figures for Percentage PIs
Calculating an outturn figure using the above method for Percentage type PIs (i.e. BV106 - Percentage of new
homes built on previously developed land) is not advisable, as in effect you will be averaging an already
average figure.
Exception – You can use the propagation method as described above for number PIs for Accumulative
Percentage PIs with no problems, where month 3 result will be the same figure for quarter 1 result, and
month 6 will be the same as quarter 2 etc. i.e. BV9 - Percentage of Organisation Tax Collected.
You would set the months to manual and the quarters and years to use months as the source, with the
calculation set to Use Latest Activated Data, as in the diagram below:
The only way to get an accurate outturn figure for the other types of Percentage PIs is to use a formula in
conjunction with two or more feeder PIs. However, you could also use the Numerator and Denominator
settings which are described later in this document; this would prevent you having the two feeder PIs.
As an example, we will use the PI BV106 (Percentage of new homes built on previously developed land) to
demonstrate this. We will assume this PI is collected on a monthly basis, for the purpose of this example.
Important – It is important to carry out the process in the following order:
1. Setting the feeder PIs
2. Setting the formula
3. Activating the data in the feeder PIs.
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Firstly, we need to create two feeder PIs which will collect the raw figures. These will eventually ‘feed’ the PI
BV106 to give a result.
Go to the PI button and select PI List.
Create feeder PI No1
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Click New.
Give the PI a code of L1BV106
Give the PI a sort code of L1BV106
Type a short name “Number of new homes built on
previously developed land”
Type a description “Feeder PI number 1 for BV106”
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Open the Settings Tab folding panel
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Set the Data type to Number
Ensure the Active box is ticked
Open the Collection Settings Tab
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Tick the Data only checkbox
Set the collection for Months to Manual Entry, interval 1
Set the Years source to Months
Set the calculation drop down to Sum all activated data Click Save
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Click the Data Tab
Under Time Periods, ensure only the Months button is pressed
Click Append and add twelve rows so you have a full year (Apr to Mar) 
Click Save
Create feeder PI No2
Now follow the above steps and create a second feeder PI, this time give it the following (you may find it
easier to copy and paste the above PI and rename the code and shortname):
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PI code of L2BV106
PI Sort code of L2BV106
Give Short name “Total number of new homes”
Description “Feeder PI number 2 for BV106” Keep the settings the same as feeder 1
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Append twelve rows as previously (they may already exist if the PI was copied) 
Click Save
Set the formula on top level BV106
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Select PI BV106 (this will already exist on the training site)
Open the Formula Tab
Tick the Formula Gauge checkbox (OK the message that appears, which is telling you that the source
of the collection settings will change from manual entry to formula)
Type the formula: L1BV106/L2BV106*100 into the Covalent Formula field
Click Save
Click on the Collection Settings tab, check that the Months and Years Source shows ‘Formula’.
The formula will divide the Feeder PI 1 (Number of new homes built on previously developed land), by Feeder
PI2 (Total number of new homes) and multiply by 100 to give an accurate % outturn.
Activate the Feeder PI data
Now, whenever data is entered into the feeder PIs and activated, the result will be displayed in the PI BV106.
When year-end is reached (i.e. 12 months or 4 quarters of activated data) an outturn figure will be produced
by Covalent.
See Formulas in Action
To see this in action enter the following data in to each of the feeder PIs:
Feeder PI 1:
Enter the value of 25 for April, May, June, July, August and 45 for the remaining seven months (tick all activate
boxes & Save).
Feeder PI 2:
Enter values of 85 for April, May, June, July, August and 60 for each of the remaining seven months (tick all
activate boxes & Save).
Select the PI BV106 Percentage of new homes built on previously developed land.
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Click Refresh, and then view the data on the Data Tab. You should see the following results:
Note how the result for the year is an accurate 52.07%
If you had asked Covalent to calculate this simply using the propagation settings, as used for Number PIs,
(i.e. average all activated data) you would find the result would be 56.04%. This is because Covalent would
be averaging % figures which are already an average for the month.
By using formulas and feeder PIs, you are using raw, number only data before the calculation is made in the
formula.
USING BRACKETS
Covalent supports the use of brackets in your formulas, so you can enter:
PI1/(PI2+PI3+PI4)*100
To add PI2, PI3 and PI4 together then divide this result by PI1 and finally divide by 100.
NUMERATOR AND DENOMINATOR COLUMNS
You can also configure a percentage or ratio PI to calculate the value from numerator and denominator
values instead of having this data in another set of feeder PIs. This is beneficial when you only need to have
feeder information stored for the current PI, but you probably wouldn’t use this if your values were used in
other percentage PIs because you would then be duplicating your data entry.
Setting up the Numerator and Denominator columns
In the Settings tab if you’ve setup your PI to be a Percentage or Ratio then you will also see a tickbox labelled
Numerator/Denominator. Tick this and you get another two fields where you can define your labels for the
two new columns. For example, using the same example as above:
Numerator is: Number of new homes built on previously developed land
Denominator is: Total number of new homes
Therefore the screen will look like the following:
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Here we’ve added the labels for these two columns.
Once that is done you need to configure how the data will be collected for this information. Click on the
Collection Settings Tab. The system will automatically configure the collection settings for the default
collections, and when you add a new collection frequency then it will also add the collections for the
numerator and denominator columns too.
Click on Add Collection – the screen that you see will depend on what other collection settings you’ve already
defined, for example, here we’ve already setup Years and Months to be collected so these are greyed out
of the menu.
If we chose Quarters: Main in the above example we would get three extra columns:
We’ve got the collection for the quarterly value, and both the numerator and denominator. This gives you
the ability to define the gauge and will be based on the values you enter for the numerator and denominator.
Next, click on the Data Tab. You have a new button in the Extra Data panel to switch on or off the new
Numerator and Denominator columns, plus targets for these columns too. This is called Percent and Ratio…
Now when you enter values against the numerator and denominator for a Percentage it will automatically
divide the numerator by the denominator and multiply by 100, and for a Ratio PI just do the division. You
don’t need to activate the value for the calculation to work, but you will need to activate the value to show
this value on the gauge, as normal.
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Here we’ve added 500 to the numerator and 8000 to the denominator, and the value has been worked out
to be 6.25%.
USING FORMULAS TOGETHER WITH NUMERATOR AND DENOMINATOR PIS
The use of formulas is still available with a numerator and denominator PI. The PIs that are part of the
formula must also have numerator and denominator columns defined.
For example you may want to work out the percentage of invoices paid for three departments and also an
overall percentage of invoices paid for the organisation.
Each of the three departments would have PIs setup with a numerator and denominator for ‘number of
invoices paid’ and ‘number of invoices’, and each one would then automatically work out their own
percentage value.
The Formula PI would also have the same numerator and denominator columns, but instead of having the
data manually entered it would be configured to come from the formula, which would add department 1 +
department 2 + department 3 to give a total number of invoices paid, and total number of invoices for the
three departments, before calculating the overall percentage.
Only PIs that are configured as numerator and denominator PIs can be used in a formula PI that is also
configured as a numerator and denominator – i.e. they’re all configured the same way, otherwise an error
will occur.
You can also use the targets on the feeder PIs to calculate the target on the formula PI, this works in exactly
the same way as any non-numerator/denominator PI and can be set using the Target Source option on the
Collection Settings, as shown here:
SEE ALSO
Online TUTORIAL
Training LESSON
PIL8
Related TOPICS
PIH3 – Create a New PI
PIH3a – Set Performance Gauges
ADH5b - Doing a PI Import
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