Project: Fruit Packing – Changeover Times
Background
This manufacturing and packing arm of a large UK retailer has a number of fruit and vegetable packing facilities across the UK that receive product in bulk from producers and re-packages it into retail packs and trays. The site had some 21 bagging and tray-packing lines. Each line consisted of a long inclined roller feed conveyor which allowed inspection of the product to take place, which then feed the inspected produce into a multi-head weighing machine. The weighed product then enters a horizontal form-fill-seal packing machine, is check-weighed and is then date coded and has an on-line printed price label attached to the bag. The final packs are then packed into plastic trays for distribution to the depots.
Issue/Problem
Packing lines have to handle a number of different raw materials every shift and each line can have as many as five changeovers per shift. The client was aware that a significant amount of time was being lost as a result of these changeovers and asked B&N to run a workshop with the aim of considerably reducing the amount of downtime associated with routine product changeovers.
Solution
Initially the workshop team measured a number of changeovers to establish base-level performance. It was found that changeovers took between 28 and 31 minutes with an average close to 30 minutes. During the course of the workshop the Team measured and on occasions micro-managed a further 24 separate changeovers on the lines to further identify what was limiting the current changeover cycles and to trial some potential improvement ideas. After measurement, these were then analyzed to determine impact on activity and non-activity periods for the various parts of the changeover cycles.
Reducing the Downtime
By analyzing the cycles the team determined that a changeover could theoretically be completed in 10-11min assuming appropriate skilled operators were available and all non-activity time was eliminated. During the team’s observation of a number of changeovers it became clear that certain operators were more adept and speedier than others in achieving the optimum times. To demonstrate the achievability of a 10 – 11m changeover time, a team were picked consisting of the most competent operators and the changeover was micro-managed by workshop team members. A changeover time of 10m 17s was achieved.
Original Changeover – 30min
Optimum changeover – 10min 17sec
Further investigation took place to determine the skills gap and associated training requirements to ensure that appropriate skills would always be available to achieve optimum times. A skills matrix was produced to aid a training program to bring all machine operators up to the standard of the current best staff.
Benefits
Based on the number of changeovers during the three months prior to the workshop and the future achievement of 12 minutes per changeover at the end of this two-week workshop an annualized saving for the site of some £69,000 was identified. Additionally it was determined that a further £160,0000 of savings could be achievable if the program were to be rolled out across the other four sites in the group.
