Hello,
You are absolutely right. When the type of Period Length is 1, then you don´t need to enter the number of days per period. I will amend my previous comment.. sorry about my mistake I did not look at the type of per.length.
Now let me explain your numbers.
You have a total of 700 CS of PIRs for the following 90 days. The daily demand is calculated as: 700 CS / 90 Days = 7.77778 CS / day.
Based on your settings, your target safety stock is equal to 30days (appliable only during the first month). So it is: 30 days x 7,77778 CS / Day = 234 CS.
Now, as you can see, the sum of those planned orders is 234 CS.
This example is not clear, because you have PIR in the past and a monthly lot size (I suppose). Try to make the same example, but I recommend to start with the PIRs in the first week of Oct. Run the MRP and you will see a more clear example...
Kind Regards,
Mariano