Observations are consolidated, reviewed and following actions are defined using different tools (Cause & Effect Diagram, IS / IS Not, Situation Mapping, differentiating between Value Added & Non Value Added operations & assembly specific requirements):
- Operations F G & H can be combined to 1 operation, hence reducing 2 operations.
- Operations K L & M can be combined to 1 operation, hence reducing 2 operations.
- Training to operator for in-process inspection in there respective cell. Self certified parts leave from the respective cell.
- List of value added operation & Non value added operations made.
- Many Inspection stages – Operation C / E / G / J /L /N are inspection stages – it is observed that independent inspection stages not required after every stage as they are non value added operations – build the concept of self certifying the parts. Hence reducing the stages from 6 to 2 (Only 2 critical stages are maintained, these are considered as Required Non value added operations), hence reducing 4 operations.
- Movement of operators & line stoppage can be avoided by adding an additional person to monitor the stock in the bins and refill as and when required as that in super market. This shall be maintained by implementation of KANBAN cards.
- Considering to Balance the process /operation time where a ever possible.
Considering all the above points’ modifications following activities are done:
- Modification in assembly fixtures initiated to combine the operation.
- Unwanted inspection stages are eliminated and modifications done in the existing 2 stages to ensure that all the product requirements are inspected.
- Assembly cells re-structured and finally the Present layout mapping as below is achieved. (Following layout is achieved)
IMPROVED SITUATION OF AIR VENT ASSEMBLY LINE
Following are the cycle time for the improved process:
Observations after the process re-structuring:
- First piece from comes out after only 204 sec from the start of assembly line.
- Thereafter time required 68 sec / part.
- Person added to refill the bins – hence no stoppage of assembly for refilling of parts.
- Manpower used 8 operators + 1 person for refilling the parts = 9 nos
- Overtime not required.
- Unnecessary stages are eliminated.
- Stages / Cycle time is tried for balancing however there is a scope for lot of balancing.
- Some Inventory still exists at T-U / V-W operations.
- Supervisor is more confident to meet customer requirements.
- Maximum Non value added operations eliminated.
- In the existing situation 415 parts can be produced against the requirement of 400 / day.
- Space utilized is reduced to 7.2 x 2.2 meters.
Quantifiable Benefits are as follows:
- First and foremost benefit customer requirement can be meet in the normal working hours. Hence the sales increased from the normal shift working without any overtime.
- Increase in production quantity from 307 to 415, generating the spare capacity for 15 nos extra.
- Reduction of manpower from 15 to 9 nos. Hence the savings of 6 x 6000 = 36000 INR ($900) / month
- Overtime payment is nil i.e. the direct saving of $ 805 / month
- Overtime 2.2 hrs x 15 operators x 37.5 INR = 1237.5 / day
- 1237.5 INR x 26 working days = 32175 INR / month ($805)
- Hence the total direct savings per annum is $ 900 + $ 805 = $ 1705 / month x 12 months = $20460 p.a.
- Inventory level is reduced, however not eliminated.
- Spare space of 4.3 x 1.1 meters generated.
- This study has helped to learn more on improvement and to implement on other assembly line.