Actual data is read in Customizing for the relevant planning scenario. You have two options for doing this:

• Read the actual data immediately, so that you can see the most up-to-date version of your actual data
• Read your actual data at a clearly-scheduled time, thus enabling you to 'refresh' your actual data when business trading closes

You cannot run an automatic Delta comparison of your data - data is only read in line with the selections that you have made previously. You can limits the amount of actual data to be read by selecting particular planning levels and by setting a realistic time limit for your actual data.