Consumption for a flock will be determined by their assigned standards. Despite the most accurate standards, the most up-to-date flock records, and the most attentive plan managers, feed consumption will not reflect what is actually happening in the house. For that reason, we need a way to "course correct" the plan over time. If the flock is not eating enough feed as we had planned, we will need to reduce consumption to allow them to eat any surplus feed and not deliver more. If we are finding that there is less feed left than we had planned then we need to increase consumption for future deliveries to make sure that flocks complete their rations on the planned age, and not before.
When ending feeds are taken after feed deliveries we have some points of data we can work with- how much was delivered and how much remains. When the flock is consuming feed in accordance with the standard, you would expect that the only feed that should be in the bin is what was just delivered. If this is not the case, then we will apply an adjustment to consumption up or down. This adjustment will take into consideration any previous ones that we have made, in an attempt to reach a median rate that will not fluctuate much.
What determines a Variance?
There are two records we will need to calculate variance- feed deliveries and ending feed. Once we have these two points of data we know how much was delivered and how much actually remains left. Whatever the difference is left is what we use to calculate the variance. Variance is calculated for every ending feed that is taken over the life of the flock. A variance will be applied to every hour of consumption for the flock, until a new ending inventory is taken, or until the difference between feed delivered and ending inventory is "0".
Feed Delivery
Live Inventory → <Selected Flock> → Feed Delivery
Feed delivery records will be imported from the staging table, once their corresponding feed order has been approved and committed.
Ending Feed
Live Inventory → <Selected Flock> → Ending Feed
Ending feed records will need to be manually entered. These ending inventories are usually taken by a delivery driver or service person, but growers may also call to report them.
Auto Consumption Adjustments
System → Feed Plan Configuration → Additional Options
There is one way to configure variance- by setting the "Auto Consumption Adjustments" fields on a feed plan configuration.
Setting minimum and maximum values will allow you to prevent the variance calculation from straying too far from the intended standard- this comes in especially handy in the event that bad data is recorded. If a user accidentally adds an ending inventory as "500" MT instead of "50", and the variance reduces consumption by 90% you are going to end up with some very hungry flocks! Set amounts in accordance with how accurate you suspect your flock records are- if history shows that your plans are usually no more than 5-10% off their intended standard then setting those variances will account for actual consumption and prevent issues caused by bad or missing data.
Should you wish to disable variance in either direction, configure either of the min or max fields to "0%". Any variance of that type (over or under intended consumption) will be set to 0% to adjust. Setting both to 0 will disable variance entirely.
There are a few things to consider when calculating variance:
- Be aware of the times on feed deliveries and ending feed- If an ending feed is recorded on before a feed delivery on the same day this will cause issues. Some customers have made it a policy to record all ending inventories at a certain, later, time of day to reduce the likelihood of this happening.
- Ending inventories taken before the start of the flock will not calculate variance- Any ending feed recorded before the start of the flock is the result of some other flock's consumption. Therefore, variance will not be calculated for these records. As a rule, we should not expect to see variance calculated until the first ending feed during the life of the flock. It is only at this point that we can determine whether the flock is on schedule, or not.
- Ending Inventories recorded for the future will not calculate variance- The only ending inventory records returned by the feed plan process are those whose dates are less than or equal to the current date and time. Ending inventories recorded on future dates are not considered, and are treated as "bad data". The ending feed form will allow us to enter ending inventories for the future, but their values will all be formatted in red font to signify this.
Calculating the Variance
Variance adjusts consumption to more accurately reflect actual consumption. Variance is recalculated during the Generation process whenever the current date coincides with a flock/house ending inventory record.
Total Actual Consumption = Total feed deliveries - Current Ending Inventory
Total Calculated Consumption = The sum of all interval consumption amounts
Variance = (total actual consumption / total calculated consumption) - 1
Adjust the variance if the variance adjusts the % maximum positive adjustment or is less than the % minimum negative adjustment.
From this point until the the next ending inventory, this variance will be used to adjust consumption
Scenarios
Feed Variance Scenario 1
When our deliveries match our ending inventories, we know that we are accurately delivering feed. Dividing 36 by 36 nets result of 1. Subtracting this from one gets us a variance of zero.
Feed Variance Scenario 2
If we are getting higher ending inventories than deliveries, we need to adjust the consumption down. In example "B", you can see that our total deliveries are less than our ending feed. This could mean that there was a surplus of feed in the bin, or that we delivered more than recorded. The software will note the 10% difference and the ration will accurately adjust the value down. Using the cumulative totals will account for any variance we already factored while we were calculating the results.
Feed Variance Scenario 3
In the final example, we can see what happens when the ending amounts are less than delivered. when this happens, the birds are exceeding their standard consumption, and are eating into their feed buffers. We note this and adjust consumption up, to deliver more feed, sooner. In this example, you can also see how using the cumulative values will course-correct itself over time, accounting for the whole life of the flock.
Reviewing / Proofing the Variance
Variance can be reviewed on the feed plan detail, until the "Auto Consumption Adjustments" band.
If an ending feed has deliveries then a variance will be calculated starting on that date and time. We will be able to see the total cumulative ending and delivered, and from there we can proof the variance using the calculations above.
