Purpose

• To outline the method and responsibilities for tracking changes to their actual effectivity.

Applicability

• All changes to be processed by this CM function.

Policy/Practice

• Change processing is not complete when a change is released to manufacture — we must know the actual effectivity (traceability):
  1. For non-interchangeable changes the exact units containing the change (and thus those that don’t) must be known.
  2. For interchangeable changes the actual effective date at a specified point in production is adequate — tracing to exact units is not necessary in most commercial environments. (Not necessarily true in some regulated environments – see FDA, DOD, NASA, etc., requirements.)
• Examples of methods for identifying the exact unit (non-interchangeable) are (pick one):
  3. Tracking to Serial Number is a very common method – “shop traveler” to Serial Number. When a change is incorporated, its number is recorded on the shop traveler. After the SN is assigned, the SNs with the change are recorded. Unit recycling may cause effectivity to be very mixed – Example: change #1326 effective at SNs 128, 130, 133, 136, 138 and up.
  4. “Make to Order” companies would typically make whole orders contain the change. If a change is to affect only part of an order, often a suffix digit is added to the order. If the ERP has an “Order Related BOM” capability, changes in the middle of an order could cause two Order Related BOMs to be created.
  5. High end (high priced)/low volume manufacturers might accompany each unit with a BOM (and keep a copy on file), thus noting all BOM changes and non-BOM changes.
  6. A new date code or lot number is assigned for each non-interchangeable change. A shop traveler – with date code/lot # attached to/accompanies each unit.
  7. Units are tagged/marked, indicating a change is present (“Mod Identification”).
     • A01 – first production unit(s)
     • A02 – first non-interchangeable change
     • A03 – second non-interchangeable change
     • B01 – first non-interchangeable change to be retrofit
       Recycling product issues solved by reassignment of Mod.
  8. Each non-interchangeable change is assigned a Mod letter. A “scratch ticket” is attached to the product. When a change is incorporated into a unit the appropriate letter is scratched. A copy of each ticket is kept by SN as shipped. Mod scratch ticket:
     • A B C D E F
     • G H J K L M
     • N O P Q R S
     • T U V W X Y
  9. Roll revision levels or part numbers and attach a traveler to each product to track revision level/part number. (Definitely not recommended, as Rev rolling and/or PN rolling are awful solutions. Can’t tell a document only change from an interchangeable change from a non-interchangeable change. Sequencing issues are often resolved by revising revision levels. A traveler is still needed or all parts must be marked or tagged with a revision level.) Not recommended!
• Production Control shall be responsible for choosing the method of tracking with CM agreement.
• Production Control will be responsible for tracking all changes by the method chosen and entering the actual effectivity into the change form or notifying CM to do this.
• The identifier chosen (SN, date code, etc.) will be included on the product nameplate. If the scratch ticket is chosen — placing it near the nameplate is acceptable.
• If product and major assemblies are both serialized (often done to prevent “cannibalizing” for warrantee fraud), Production Control will be responsible for keeping track of actual SN(s) into SN and making that information available to the rest of the company.

Procedure

• See flow diagram, change form and change form instructions in other standards.

Primary Responsibility

• Production Control will be responsible for keeping this standard current.
• Production Control planners may take exception to this standard by noting on the change form why that was done.

Authorization