Hi, I'm a newbie here, please be kind with my first post.   I need help to identify which customer has 1 or more product switch and I have attached a sample data as well as 2 output tables I need to produce. Some of the data from the spreadsheet attachment is copied below.   Input Data ID PROD_CODE Prod_First_use_mth Prod_Last_use_mth 2 ABC06 1-Mar-09 1-May-11 2 ABC08 1-Jun-11 1-Apr-17 32 ABC07 1-Jan-09 1-Jan-12 32 ABC08 1-Mar-12 1-Apr-17 48 BMX02 1-Apr-09 1-May-09 48 ABC06 1-Jan-09 1-Apr-17 90 ABC06 1-Jan-09 1-Jul-12 90 ABC07 1-Aug-12 1-Apr-17 90 DCA02 1-Mar-09 1-Mar-13 90 QAM01 1-Jan-09 1-Aug-16 90 QAM02 1-Dec-09 1-Apr-17   What I'm after for the first output is finding customers who switch from using one product to another within plus or minus 4 months like in the case of customer 48. The input data contain the customer ID and the product first and last use month-year   Output Data 1 ID FIRST PROD SWITCH FROM FIRST PROD SWITCH FROM DATE FIRST PROD SWITCH TO FIRST PROD SWITCH TO DATE 2 ABC06 1-May-11 ABC08 1-Jun-11 32 ABC07 1-Jan-12 ABC08 1-Mar-12 48 BMX02 1-May-09 ABC06 1-Jan-09 90 QAM01 1-Jan-09 ABC06 1-Feb-09 90 ABC06 1-Jul-12 ABC07 1-Aug-12 The second output is pivoting the data to identify all customers who have >= 2 products spend within the last 6 months (DEC16-MAY17). Some customers do have more than 4 products but I just put down 4 here for illustration.    Output Data 2 ID CURR PROD #1 CURR PROD 1ST SPEND #1 CURR PROD LAST SPEND #1 CURR PROD  #2 CURR PROD 1ST SPEND #2 CURR PROD LAST SPEND #2 CURR PROD #3 CURR PROD 1ST SPEND #3 CURR PROD LAST SPEND #3 CURR PROD  #4 CURR PROD 1ST SPEND #4 CURR PROD LAST SPEND #4 90 QAM02 1-Dec-09 1-Apr-17 ABC07 1-Aug-12 1-Apr-17               Hope I have been clear in my description, let me know if I may have missed anything.   Thank you,   Peter ... View more