First of all, thank you for the help. I already try the possibilities that you reffer but i still have the problem. Basically, i have a source that can produce productA and productB connected to 2 servers at the same time (paralell servers). In a table a have a columm that identifies the product followed by one that identifies all the servers in use and another one for the processing time. Basically i need for each server (in the processing time information) to read the type of product that´s entering and then see the current server, but i can´t get the correct value. The server reference in the table is well associated to the server in use, but the expression used is random, i mean it is not getting the value of the true produc but instead is getting the possible lower value. How can i say to each server that the procesing time row is the one that have, let´s say, server 1 and productA?
Sorry for bothering and once again thank you.