The process drills to 1.13 Fetch daily Ref CPI, the process spec. The flow entering from the left is daily Ref CPI, drawn against its source on the context diagram. Ref CPI (S3) has an arrow each way: the run merges what it fetches into what the store already holds. Ref CPI (S3) is not written when the fetched series ends before the last day of the second month after the latest month of CPI history (S8), or when the merged series has a gap of more than one calendar day or is shorter than what the store already held.