Case Study 3 Aylesbury Pressings , Roddy Mcguinn And Martin Toher.

Case Study 3: Aylesbury Pressings Case Studies, Bsc Hons Quality Management and Technology Authors :Roddy McGuinn (s00093607) and Martin Toher(s00093928 )

12/5/2009

Using the Lean Principles as a framework, what improvements do you consider that the management team at Aylesbury should be giving priority to, and why? Introduction Aylesbury pressings is a manufacturing company that produces automotive metal components that supplies the automobile industry. The business displays characteristics of a high volume high variety operation as its’ products are considered runners or repeaters with batch ranges of between 150-500 parts and a variety of 80 main products many of which have several versions. This complex environment posses some difficult challenges for the Aylesbury pressings operation. Many of the difficulties faced by Aylesbury pressings can be alleviated by using some techniques associated with lean manufacturing. Suggested improvements 1/ Quality: The Lean philosophy identifies seven different forms of waste (muda), these are over production, waiting time, transport, process, inventory, motion and defectives. One obvious source of waste in the operation is in the production of defectives in the pressing stage of operations. Many of the dies used are old and difficult to adjust which results in defective materials being produced. These dies should be replaced as a matter of urgency and should be the first priority of the management team. This is so because if the output of this early stage of production is of a high quality and the process itself controlled, it will make all subsequent stages of production much easier to improve as the supply of materials to these stages will be more predictable and of higher quality. Quality, right first time does not seem to be a major priority for Aylesbury pressings as only 4 of the 280 staff are actually employed doing quality work. 2/ Involvement of all staff: The level of suggestions for improvements coming from staff is very low and few if any visual indictors of quality are being used. This is a strong indicator that all staff are not being encouraged to participate in process improvement. One more subtle area of concern is with the use of poka yoke (Error proofing) systems. These were implemented by an outside consultant but one of the key ideas behind pokayoke is that the operations staff themselves are involved in coming up with error proofing ideas rather than having ideas imposed without the involvement of all staff. This lack of staff involvement is also reflected the manner in which the Standard operating procedures (SOPs) were completed. The SOPs used within the operation were completed by the Kaizen promotion office but little consideration was given to the expertise of operations staff in this process. A recent audit showed that the SOPs were in many cases not being followed. This may be expected if the SOPs are impractical and did not consider the capability of operators or machinery. It is therefore very important that all staff be involved in the improvement process this is one of the key themes in the lean manufacturing philosophy. This can be viewed as adopting basic working practices which will operationalise the involvement of all staff. 2/ Reduction of set up and Change over times: A lot of time is wasted in Aylesbury pressings in setting up a run or completing change over activities. Excess time spent

completing these tasks adds to the overall cost of the product and does not add value. Some of the activities and times associated with these are as follows: • •

• •

Blanking process Change over time 15 minutes. Pressing process sampling time of 10 minutes and a 1% scrap rate associated with each change over cycle. The case study also states that some Pressing changeovers take between 30 and 60 minutes. Benchmarking has demonstrated that this time is excessive with little value being added. Painting process takes around 90 minutes to complete. In that time only 3 minutes is actually spent painting, the remainder of the time is spent setting up for a run or removing painted parts once a run is complete.

As the operation currently stands much of the work completed for set up and change over activities are probably being completed while the production machinery is idle. This is referred to as internal work in the SMED approach. Time spent in this manner leaves less value added time for production and is a form of waste called waiting time. These inefficacies can be addressed by using a single minute exchange of die (SMED) approach. Where possible tasks for set up and change over should be completed while the production machinery is still running, this is called external work. Tasks which could be completed in this manner include pre set tools instead of having to set tools when the process is stopped, the use of standard fixtures and devices to speed changeover times. This can also be aided by having the materials within easy reach when required which is linked to layout. 3/ Total Productive Maintenance: Some of the machinery in the pressing stage of the operation is running at 80% of their rated efficiency. Maintenance staff have currently a downtime target of less than 5%. The introduction of total productive maintenance will involve every staff member in finding ways to improve the process. Many routine maintenance tasks can be completed by the operators themselves with the more complex tasks being completed by specialist engineers. These more specialised staff will then have more time to dedicate to the overall improvement of the maintenance process. 4/ Inventory Reduction: There are considerable levels of inventory being held within the operation, after pressing, production materials are moved to a warehouse and stored, buffer inventories are held before Assembly stage and each cell within the assembly process has its own inventory. Inventory is kept at every intermediate stage and the dispatch process holds additional inventory ranging from 2 hours to 2 weeks. The lean philosophy regards the holding of inventory as a form of waste. This is true because inventory ties up capital, there is a cost to insure, maintain and store inventory and there is always the risk of inventory becoming damaged or becoming obsolete. Inventory may be considered as a blanket of obscurity that masks problems that exist within the operation as a whole. Many of the problems with Aylesbury pressings are being compensated for by holding excess inventory at every stage which will ultimately fail in the long term. These problems include poor die quality, excessively long change over times of between 30 and 60 minutes, Standard operating procedures not being followed (Perhaps because they were poorly written), insufficient flexibility and poor plant layout. The inventory levels within the operation should be gradually reduced overtime, this will have the effect of exposing the problems that exist and a concerted effort can be undertaken to permanently resolve these issues. This will initially slow production but this will be more than compensated for in the long run by having a much more efficient operation.

5/ Levelled scheduling ,Mixed Modelling and Synchronisation: These ideas are best applied to operations whose products may be described as runners and/or repeaters, these are products which are produced daily or at very frequent intervals. As such the Aylesbury pressings operation is ideally suited to levelled scheduling, synchronisation and mixed modelling methodologies. The idea behind levelled scheduling is to spread the production of a batch over a wider period of time. For example if a batch size of 300 units was required for part A , then a batch size of 100 could be run on day 1, a second batch size of 100 on day 2 and a third batch size of 100 run on day 3. With smaller batch sizes inventory can be reduced and the throughput time for each smaller batch will also be reduced. This can have the added benefit of making the production schedule much more stable as more of the same products are produced each day and the in turn makes the process less variable. With reduced variability the process is itself simplified, this simplification combined with repetition and experience results in staff which are much more competent at daily tasks which in turn improves quality and reduces waste and costs. 6/ Value Stream Mapping: At the most fundamental level any process in an organisation can be regarded as either adding value or adding cost. End to end system mapping (Value steam mapping) would allow Aylesbury pressings to quantify how much time of a products throughput time is actually spent adding value and how much is adding cost. The throughput time for some products is likely to be very high with very little time spent adding value as some materials are held between 1 day and 4 months between the pressing and assembly operations. This is one of the 7 forms of waste which is waiting time. Value stream mapping takes a holistic look at the entire operation, firstly a process is selected for analysis, then the path of material through the entire operation is physically mapped the flow of information that allows that drives the process is also recorded. This stage is called the current stage map and describes the operation in its present state. Using this map a more detailed diagnosis of the problems within the operation will occur and new opportunities for process optimisation can be identified. A new ideal state map of the process is then completed and improvements implemented. 7/ Operation layout: The operation layout in its present state may not the most efficient. The press shop and blanking cell are located in separate areas away from assembly facilities. This was originally designed in this manner as these there is a lot of noise associated with these activities. This should be reviewed to see if all processes can be arranged closer together. It is not clear that noise is an entirely justified reason for the present layout. The process of assembly itself must generate considerable noise as it involves drilling and punching steps. Excess noise may be addressed through the use of personnel protective equipment and insulation materials. As the different processes are presently arranged there is unnecessary motion in the manufacturing process which is a form waste and there is the addition risk of damage to inventory when the unnecessary motion occurs. Another area which could be improved is within the pressing process, some types manufacture involves the manual movement between different presses, the possibility of automating this process should be considered. A key technique in the lean philosophy is simplification, where possible processes should be simplified and made more efficient. As the operation is designed at present there is an assembly stage followed by a painting stage and then a final assembly stage. The possibility of painting first and then having a single assembly stage should be explored, however

the quality of the product not be compromised in pursuing this change. Any damage to painted parts would render this change counterproductive. Discussion The Aylesbury pressings operation is facing a difficult situation, not only has it a high volume high variety operation but many of its customers are trying to micro manage the internal processes which has resulted a highly complex environment with many different strategies being pursued. Some efforts at improvement have been made and have been partially successful, for example there has been a reduction in the defect rate from 40,000 parts per million to 1600 parts per million, reduction in the number of samples being taken through the use of statistical process control and the supplier development programme. Another encouraging development is the use of Kaizen events, these did involve a range of staff and resulted initially at least in a 32% reduction in inventory levels and a reduction in lead time. However other efforts at improvement have been much less successful. The completion of Standard operating procedures has had limited success, and Aylesbury does seem to have difficulty in sustaining many of the quality improvement projects introduced. This is evidenced by the fact that many of the gains brought about by the Kaizen events have begun to be lost. Another example is with the 5 S programme. The 5 S programme is outlined as follows: 1. 2. 3. 4.

Sort (Seiri) remove what is not required Straighten (Seiton) Arrange things so that they can be accessed easily. Shine (Seiso) Keep areas neat and clean Standardise (Seiketsu) Perpetual neatness. 5. And lastly Sustain (Shitsuke) maintaining standards. Initially this was quite successful but there has been little emphasise placed on the sustain part of the 5 S programme. The operation has opted to use “Rounds” of 5 S programmes which means in practice that things improve for a while but will ultimately relapse in to older less optimal patterns. The only way this can be corrected is though on ongoing commitment to improve quality involving everyone in the operation with clearly communicated goals and objectives which are measured on an ongoing basis and not just at intermittent intervals. This will help in sustaining quality improvements. The operation is currently using an MRP II system to plan the production requirements of the plant which is excellent at planning but relatively poor at controlling the operation. MRP type systems are ideally suited to push type production systems with fixed lead times and a master production schedule. Just in time production is driven by actual orders from customers and this a pull type system where materials are pulled through each stage of production from a stage further along the process in response to a customer order. It uses simple controls like kanbans which the operation is using to some extent already. Ideally it would be best to use the MRP II system to complete planning and use just in time techniques for internal control. Conclusion The key goal for Aylesbury pressings is to reduce cost. This can be best achieved by moving to a pull type production system with low inventory. In order to facilitate this change product quality must be improved, efficiency needs to be improved by reducing set up times and adopting a Total productive maintenance system. Every

staff member must be included and valued in this process and management must demonstrate an unwavering commitment towards sustaining improvement.