How to manage 4M change in the automotive industry?

Purpose of 4M change:

To record 4M Changes (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 is generated 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 a product or process is defined as the ‘man, material, machine and method used for’ and is not as per control plan, work instruction, skill matrix, and customer approval.

What is 4M Change Management?

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

What are the 4M in Change Management?

Man, Machine, Material and Method are the 4M in change management. Man represents the operator who operates the machine. The machine represents the equipment used to manufacture the product. Both machines & tools come in this category. In material comes the raw material used to produce the product. The method, includes the inspection method, packing method, process parameter and manufacturing process.

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 :

  • The machine under Plan Maintenance 
  • Tool under Plan Maintenance
  • New operator employed on machine
  • Operator working after a long leave
  • The operator left the workplace due to an urgent work
  • New instrument used
  • New machine used

Learn about Machine Maintenance and Tool Maintenance. procedures.

Un-plan Change (Unexpected Change):

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

Example of Un-plan change :

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

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

  • The respective team informs to 4’M change responsible person about any kind of changes in man, material, method and machine that happen in his area.
  • The change details of Man, Material, Method, and Machine will be highlighted on the 4’M change control board.
  •  Identify man change as per the man-machine matrix.
  • The 4’M change 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, the 4’M change responsible person shall fill the 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 is to be given to concerned departments and control action is to be taken as per the WI.  

Benefits of 4M change recording:

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

Man change examples in 4M change:

  1. The operator is on leave with information
  2. The operator is on leave without information (start of shift)
  3. New operator working on machine
  4. The operator is on long leave ( More than 45 days)
  5. The operator leaves the workplace due to urgent work.
  6. The operator suddenly leave the workplace due to an accident
  7. The operator suddenly leave the workplace due to illness

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

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

Machine ( Tool ) change examples in 4M change:

  • The machine is 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 sources
  • Different grade materials used
  • Process parameter change
  • Layout change
  • Process method change
  • Inspection method change
  • Packing method change

WI for 4M Change:

4m change wi
WI for 4M change
WI for 4M change
WI for 4M change
WI for 4M change


In the Tracking sheet, we prepare a summary of all the changes in the process & their detail. It contains the date of change starts, Type of change, changes in the description, What action was taken during the change, Machine or tool detail, Part name, Retroactive record, Containment record & dispatch detail etc. It is also called 4M change record sheet.

4M Change Tracking Sheet

4M change format in Excel:


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 the change starts, Type of change, changes in the description, What action was taken during the 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 the operator and process (machine). By this matrix, the supervisor can easily find out which operator is capable of which process to operate the machine.  It is also called a skill matrix.

Man machine matrix

What is Retroactive Inspection in 4M change?

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

The record of retroactive inspection is maintained in the below format. In this format, we record the total inspection quantity, OK quantity, and 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 happens and inspecting the sample pieces for approval. Approval should be taken from the Quality Head, Plant Head or customer. 

4M Change Approval Format:      

4M change set up approval format

4M Change Tag:

It is the tag used to identify the material which is under 4M change. It contains the details of the 4M change so that it can be traced later.

4M Change Tag

4M change management questions and answers

Definition and implementation of changing management

Do you define unexpected change (unusual) and planned change clearly?

Sub Questions
4M change procedure defining changes, category of changes (Availability of
4M change WI)
Categorization of changes into planned/unplanned changes
Actions to be taken at the change point
Display of definition of changes in shop floor
Visual control of changes (4M change indication)
4M Change Information rule
Awareness of change management among the shop floor personnel
Traceability system (traceability through invoice no, lot no, route card, etc.)

Do you define procedure (rules applied from sharing information to result confirmation) at change occurrence?

Sub Question
Evidence of implementation of actions: – Record of changes (4M change record), evidence of signatures of quality and production head
approval of quality head during 4M changes
Evidence of implementation

Do you record product quality check results to ensure traceability? Incl retroactive checks

Sub Question
Check the record of parts produced after the change
Retroactive check record in case of unplanned (unexpected) changes (criteria for checking dimensional check – how many parts are to be checked dimensionally in case of retroactive check)
Traceability to invoice: Yes/No

Definition and control method for the initial part:

Do you define and control the initial part clearly?

Sub Question
Definition of the initial part (Up to pilot lot)
Initial part control – separate locked area, identification tags
Initial part control – log of initial parts

Do you control initial parts separately and make quality records about them? (both internal and outsourced processes are included)

Sub Question
Separate tags to identify initial parts
Inspection report of initial parts
Separate locked area
Summary of initial parts prepared, sent to customer and balance quantity. Action taken of balance quantity after customer feedback.

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