Step6 Root cause analysis


1, Sub process analysis
    a) Zoom in on the problematic sub processes
    b) Identify all failure modes
    c) Perform restoration for obvious failure modes detected during Genba.
2. Perform Why-Why Analysis or other analysis tools for each failure mode.
3. Restoration needed only when
    a) This is the Spec. need
    b) This is what we found (Not per spec)
    c) Corrective action: Restoration per spec (All dimension shall be quantified.)
    d) Identify permanent corrective action to prevent recurrence.
4. Result for restoration: Validate result of restoration
    a) Result 1 is the physical outcome of the restoration
    a1) The restoration will bring back accurancy to within +-o.5mil or force with +- 10kg/cm square
    a2) Validate that the above is obtained
    a3) If not obtainable, then identify what has changed before proceeding.
    b) Result 2 is the final outcome on defect elimination
    b1) If (a) is fully characterized, the result is Given and we will definitely see the improvement.
    b2) If not, then identify what has changed before repeating restoration.
Understand operating functions and principles of the equipment or process.
-Perform step by step functional sequencing mapping of the equipment or process.
-Perform detailed process mapping of the equipment or process.