Data Flow AR500P

Here is a complete cross-reference matrix showing every program in the AR500 suite (including the ones you provided) and exactly how each program touches every physical file / table.

Program	ARDETL	ARCUST	ARCONT	GSTABL	ARCWRK	ARCUSP	SA5SHX	?9?ARC500	?9?AR500X	?9?AR500D / ?9?AR500C	?9?ARATBS	PRINT (spooled)	Side Effects / Notes
AR500P	–	Read (validation)	Read + Write (updates ACDATE)	Read	–	–	–	–	–	–	–	–	Updates last ageing date in every ARCONT
AR390	Update (writes ADAGE + bucket moves)	Update (writes AGE(1–5) packed buckets + high-balance)	Read	Read	–	–	–	–	–	–	–	–	Only program that permanently changes live A/R data
AR5004	–	Read (primary cycle)	–	–	Read	–	–	Create + Write (385-byte extract)	–	–	–	–	Builds filtered customer work file
AR5007	Read (primary)	–	–	–	–	–	–	Update (writes NOD flag to pos 385) + Read	Create + Write (138-byte enriched detail)	–	–	–	Injects NOD + sort keys
#GSORT	–	–	–	–	–	–	–	Read	Read	Create + Write (sorted versions)	–	–	Two sorts: detail → AR500D, master → AR500C
AR750	–	Read (AR500C)	Read	Read	–	Read	–	Read (AR500C)	Read (AR500D)	–	–	Write	By Customer # – current production layout
AR502	–	Read (AR500C)	Read	Read	–	–	–	Read (AR500C)	Read (AR500D)	–	–	Write	By Name (alpha)
AR501	–	Read (AR500C)	Read	Read	–	–	Read	Read (AR500C)	Read (AR500D)	–	Write	Write	By Salesman + optional Excel export

Legend

• Read = opened for input only
• Update = opened for update (records modified)
• Create + Write = file is cleared/re-created and written to
• Write = spooled output or work file output
• – = not touched

Key Takeaways

• Only AR390 permanently modifies live production data (ARDETL + ARCUST)
• AR500P is the only other program that writes to a live file (ARCONT.ACDATE)
• All other programs are read-only on live files and only write to temporary work files or spooled output
• The ?9? files are all temporary and automatically deleted at job end

This matrix is extremely useful for impact analysis, modernisation planning, and regression testing.