Direct SAP table update issues

Hello Experts,

    Currently, in my customer system i see one program for slotting, they are updating SAP standard table (SCM EWM) directly using below

    statement.

      "update /SAPAPO/MATLWH set rsqty = zmax_qty where matid = mat_wa_chunk-matid and scuguid = mat_wa_chunk-entitled_id."

      I see that program is there in production from last almost 2 years and that is product update program which has to run periodically.

      As per my knowledge, this is not acceptable. Can you please share me your thoughts, what kind of problems will occur and pre-defined errors

      with direct data base table update?

      What should we do now on this?

     Thank you in advance.