How to manage 4M change in the automotive industry?

Purpose of 4M change:

To record 4M Change (Operator change, machine change, tool change, material & method change) management for expected change ( new operator, operator on leave, machine/tool PM, New machine, new gauge & new instrument) and unexpected changes (Tool breakage, power failure, machine breakdown etc.). If any issue generate later, we can easily track the change detail through 4M change management.

Scope of 4M change:

Applicable for all internal changes in process & bought out parts (BOP)

Responsibility of 4M Change: 

1Change Point Control BoardSupervisorDaily
2Change ApprovalPlant Head / Quality HeadDaily

Definition of Change :

Change related to product or process is defined as the ‘man, material, machine and method used for’ is not as per control plan, work instruction, skill matrix and customer approval.

What is 4M Change Management?

4 M Change Management is the systematic approach to deal the changes in Man , Material, Machine and Method.

Plan Change (Expected Change):

Change that occurs with prior information to the concerned person and defined action is taken to control the occurrence of non-conformity of product at the change point.

Example of Plan change :

  • Machine under Plan Maintenance 
  • Tool under Plan Maintenance
  • New operator employed on machine
  • Operator working after long leave
  • New instrument used
  • New machine used

Un-plan Change (Unexpected Change):

Change that occurs without prior information to the concerned person and sudden defined action is required to control the occurrence of non-conformity of product at the change point.   

Example of Un-plan change :

  • Machine under Breakdown
  • Tool / Die under Breakdown
  • Tool breakage
  • Power Failure
  • Different grade material used
  • Unapproved material source used

If any changes are done in Man, Machine, Material or Method related to process happens, the change shall be immediately updated on the 4’M change monitoring board & recorded in 4’M Change Tracking Sheet.

  • The respective team inform to 4’M change responsible person about any kind of changes in man, material, method and machine which happen in his area.
  • The change details of Man, Material, Method, and Machine are to be highlighted on 4’M change control board.
  •  Identify man change as per man- machine matrix.
  • The 4’M change the responsible person shall update the 4’M change tracking sheet within 30 minutes and take suitable action as per 4’M WI.
  • If No change is there, 4’M change responsible person shall fill 4’M tracking sheet with green color and if there is a change he shall fill it with red color.
  • In case of any change, information to be given to concerned departments and control action to be taken as per the WI.  

Benefits of 4M change recording:

  • Easy to trace defect at supplier end.
  • In the situation of recall at OEM, it also help to detect the defective products.
  • It provide confidence to OEM and Tear1 company when it get 4M change records timely from its supplier.
  • Reduction in rejection, rework.


Man change examples in 4M change:

  1. Operator on leave with information
  2. Operator on leave without information (start of shift)
  3. New operator working on machine
  4. Operator on long leave ( More than 45 days)
  5. Operator suddenly leave workplace due to accident
  6. Operator suddenly leave workplace due to illness

In above examples point no 1 to 4 are planned change and point no 5 to 6 are unplanned change. If we use same skill level operator in all conditions, then it is OK & do setup approval only. But if we have to use under skill operator then it becomes an abnormal situation. Then take containment action (100% visual inspection & 5 parts recording) also of that day.

In case of new operator provide training as per operation standard and take containment action of all production of that day. For unplanned changes, take retroactive inspection also of all parts from last inspection.

Machine ( Tool ) change examples in 4M change:

  • Machine under preventive maintenance.
  • Machine under breakdown
  • New machine installed
  • Tool under preventive maintenance
  • Tool under breakdown
  • New tool used

Material & Method change example in 4M change:

  • Material received from other approved source
  • Material received from other unapproved source
  • Different grade material used
  • Process parameter change
  • Layout change
  • Process method change


In the Tracking sheet, we prepare a summary of all the changes in the process & their detail. It contains date of change starts, Type of change, changes in the description, What action was taken during change, Machine or tool detail, Part name, Retroactive record, Containment record & dispatch detail etc.

4M Change Tracking Sheet


In the 4M change control board, we update all the changes in the process & their detail within 30 minutes of change. It contains the date & time of change starts, Type of change, changes in the description, What action was taken during change, Machine or tool detail, Part name, Retroactive check record, Containment record & dispatch detail etc.

4M Change Board
4M change board


It is the matrix of operator and process (machine). By this matrix, the supervisor can easily find out which operator is capable for which process to operate the machine.  It is also called skill matrix.

Man machine matrix

What is Retroactive Inspection in 4M change?

Retroactive inspection is to check the suspected parts which are made before any unplanned change or any abnormal change happen.

The record of retroactive inspection is maintained in the below format. In this format we record the total inspection quantity, OK quantity, Rejected and rework quantities. Also maintain records of sample quantity as per decided in 4M change WI.

Retroactive check reocrd


It is the Approval of the process when any process is restarted after any change happened and inspecting the sample pieces for approval. Approval should be taken from Quality Head, Plant Head or customer. 

4M Change Approval Format:      

4M change set up approval format

For any Format requirement about 4M change management, Leave a message in comment.

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