Effect analyses are used to view the results of the sows in the current or last litter sorted by, for example, Days from weaning to service or live born in last litter. From there you can analyze e.g. the effect the number of days from weaning to service has on the next litter results.
It is possible to create your own effect analysis if you want to tailor the current analyses to your needs. Before making any changes to the analyses you should create your own layout.
You find the effect analysis under "Analysis sows" and the choose "Effect analysis", there are some standard analysis in PigVision and you can choose one of these. When you have opened one of these you click "Calculate" and you can see the result of the analysis. You can click on the different numbers in the analysis and see the formula behind the calculation. In the bottom left corner you can set up limits for the analysis, for example on the race or the litter number.