Background
This multinational pharmaceutical and OTC medicine business also manufactures a number of leading brand oral care products at one of its sites. The site had installed a number of high-speed tube filling and packing lines that had historically been running at efficiencies in the 38 to 50% OEE range. The site produces in excess of 1000 different product and pack variations for both the UK and international markets. The in-house CI team had been focussed very much on reducing headcount in the period immediately prior to the involvement of Lauras, but were beginning to look more closely at the effects of this on packing line efficiencies.
Lauras International was asked to come to the paste manufacture site and assess the opportunity for increasing the OEE of the packing lines to 70%, reviewing the manufacturing, packing and planning operations.
Assessment
Lauras Consultants attended the site for two weeks and carried out detailed measurement of actual running of the manufacturing area together with each of the high speed packing lines to confirm the current base levels of performance. Historical performance and downtime data was also analysed in order to verify that Lauras’ observations were backed up by past experience:
- It became clear that although the throughput bottleneck at the time of the assessment was the high speed packing lines, once an OEE of 60% had been reached for these the bottleneck would then become the product manufacturing area.
- Routine planning and operations meetings were also attended by the Lauras team to assess their efficacy and the effectiveness in analysing and resolving problems as they occurred.
- Sales and volume forecasts were examined and a capacity model was produced to determine the required throughputs from manufacturing, filling and packing. The findings from the assessment and recommendations were communicated to the site senior management team via a formal presentation.
Problem/Issue
The mixing plant was specified and designed to run continuously at 4000 kgs/hr, but when first installed it was initially run at considerably less than this throughput. The volume requirements from the continuous mixer had grown significantly. However, as the throughput settings were turned up it was found that the number of short stops increased and these prevented the plant from reaching the originally specified throughput level. The result, typically the plant was set to run at only 3,200kg/hr. In the three months prior to the Lauras BID workshops the overall output averaged only 2200 kgs/hr with an OEE of less than 50%. The stoppages were found to be due to the powder-feed systems being unable to keep within the tolerances specified. Eight to ten stoppages per hour were the norm, with a manual reset of the plant being required on each occasion. If the operator, due to other duties or being at break, was not immediately available to carry out the reset, the plant could be left at a standstill for up to 20 minutes.
Root Cause Analysis
A team was put together including experienced plant operators, technicians and area management to work on these problems. A number of Problem, Cause Solution (PCS) exercises were carried out to find the root causes for the large number of stoppages associated with the powder feed systems.
Root causes determined included: control system settings not optimised, feed systems unable to run at the desired maximum speed, bulk density variations and line blockages caused by valve timings not being optimally set.
Solution
The Lauras team recommended to the client that a programme of three BID workshops should be undertaken in order to achieve the required uplift in performance.
- Workshop One would focus on improving the OEE of the high speed packing lines until the capacity ceiling in upstream manufacturing operations became the primary cause of downtime or utilisation constraints within the packing area.
- Workshop Two would involve maximising the output of the manufacturing area by ensuring the plant was running at its maximum speed and availability by the use of Lauras tools to eliminate the root causes of recurring downtime and speed limiting problems and to reduce mixer cycle times wherever possible.
- Workshop Three would examine the planning system and adherence performance with the aim of devising and implementing a series of planning rules designed to ensure that planned downtime was minimised on the high speed packing lines. Additionally, fixed repeating schedules of production would also be investigated during this third workshop.
Benefits
Following this workshop the OEE of the continuous plant increased by 38%
Based on the following year’s planned volumes the required running hours dropped by over 2000 hours.
The plant ran continuously at 4000 kg/hr and the number of stoppage alarms dropped from an average of eight to ten per hour down to below two.