Lean Aerospace Implementation at Messier Dowty
The Messier-Dowty Aerospace Montreal plant is dedicated to the manufacture of big gears for the Airbus A340 and the Airbus A320 families.
Sylvie Langlois
is a graduate Metallurgical Engineer (1980), and worked in metallurgical industries as a process and technical manager. She was hired in 1991 by Messier-Dowty as part of the starting team and has held various positions including: technical support for the machine shop, production planning, quality and now Lean.
Setting the Scene - Messier-Dowty Aerospace (MDM)
Its Products, Processes and Equipment
Messier-Dowty Aerospace (MD) is part of the Snecma Group. Messier-Dowty Aerospace is comprised of eight operational sites: in France (Velizy/Bidos), the United Kingdom (Gloucester), Canada (Toronto/Montreal), the United States (Seattle), Singapore and China (Suzhou). Messier-Dowty Aerospace has a long and successful history in the design, development, production and support of aircraft landing gear systems.
The Organisation
Our Montreal plant was built in 1991 specifically for the Airbus 340. This plant was designed to handle big parts that cannot be produced elsewhere in the corporation.
In terms of organisational structure, MDM was designed as a flat organisation with only one management level. It was based on the concept of empowered teams. The teams need to work like small business units. Because there are no foreman or cell leaders, team members are called on to make decisions that fit within their scope of expertise.
This operational design passed through several improvement processes and changes over time but the foundation always stayed constant: teamwork, employee empowerment and a flat organization.
Our people and our organization have been the key to our successes in meeting the different challenges we faced through the years. We are known throughout the corporation as very reactive, flexible and customer focused. We also have the reputation of being a bit of a corporate black sheep as we always challenge the status quo in our ongoing search for improvement.
The Products
The Messier-Dowty Aerospace Montreal plant is dedicated to the manufacture of big gears for the Airbus A340 and the Airbus A320 families. The A340 plane flew for the first time in 1992. At that time, the A340 main fitting (top part of the gear) was the biggest gear ever to be machined in one piece.
To give you an idea of the size of the parts, the forging, from which the A340 main fitting is machined, weights 7.5 tons. At the end of the machining process, the weight of the part is only 1.5 tons. There are 6 tons of chips generated during the process. The part itself has the general profile of a rectangular triangle 10 feet high and 4 feet wide.
The Equipment and the Processes
Everything is huge in our facility. We have 2 big profilers (milling machines) that can machine 6 parts simultaneously. These machines were delivered with a mirror image capability to produce 3 right and 3 left hand parts. As an airplane needs 1 left and 1 right hand gear, this was a big advantage to us. It was the state of the art in terms of technology at the time we bought these machines. Each machine cost $10 million and, because they look so useful and powerful, with a big capacity, we bought two of them. They were the pride of the plant and the center of attention.
We call them "mammoths" now (or "monuments" in Lean terminology). They are big and dedicated to lot production. They cannot be moved even though each machine is using the space of two or three milling machines. The time to complete one operation on these machines is counted in days, not in hours (it needs 120 hours to profile an A340 main fitting). That's why we have to produce 6 parts at a time to justify the machining time. As a result we are able to deliver 6 parts to the next machining center every week.
Do you start to have an idea why we call those machines, "mammoths"? They are so big and lot-production oriented they cannot be adapted to our new reality. They are exactly like the mammoths that were caught in ice because they were too big and specialized to adapt themselves to new weather conditions. They just died. Are there any readers interested in buying these powerful machines? We can give you a good deal!
All joking aside, most of our equipment is huge. The machining centers have foundations with spikes reaching down into the rock at a depth of between 50 and 70 feet. There's no question of moving them. Because nobody knew about Lean when the machines were installed, they were simply grouped by technology. All the lathes together; the B axis, one place, the A axis another, and so on. Aesthetically, it looks nice but in terms of flow, it significantly increases the distance a part has to move before completion. We also have one of the largest hardening furnaces in Canada as well as big baths for chrome and CAD plating.
As I said previously, an A340 main fitting is 10 feet high by 4 feet wide. It occupies 40 square feet. The A320 is a little smaller but still uses 20 square feet. So you can imagine that inventory quickly became a headache for production people. They were endlessly calling for more space. Because of the weight of the components, people need lift trucks and overhead cranes to handle them. Again, there were lots of requests for more of this lifting equipment. Is this sounding familiar to some of you?
The manufacturing process involves around 60 operations. In 2001, the lead-time to produce an A340 was 26 weeks and 17 weeks for an A320. Each part is quite complex with over 900 dimensions to meet. There are also a number of special processing parameters (heat treatment, shot peening, chrome and cad plating, painting, assembly). These are not easy pieces to produce.
The Planning Reality
We have no direct customers because we deliver parts to our Gloucester or Bidos plants for final assembly. The volume to be delivered is quite low with less than 100 sets per year for each product. Our monthly demand is variable. Some months we deliver only 2 sets of A340 while others may require 8 sets. The situation is the same for the A320. As well, our internal customers issue a lot of changes to the orders, sometimes with less then a month notice. When your lead-time is more then 4 months, it's very hard to manage last minute changes. However, considering that they are the ones who are dealing with the end customer and issuing the purchase orders, we have had to deal with those requests.
Once we began our Lean journey, we started to think it all through and actually began challenging our customer on the change-to-order process.
So that's our reality, a low volume of big and complex parts with a variable demand and last minute changes.
The Start of Our Lean Journey
In 2001, we were faced with a lot of problems. We had a hard time meeting our deliveries. Our inventory was high. We were struggling to find room to store all the parts. We lacked the capacity to face the future demands that Airbus forecast. Machine downtimes were hitting us severely. We were always in a recovery mode. The renewal of the contract for the Airbus A320 was coming up and there was a lot of pressure from Airbus to decrease both our price and lead-time. That contract for A320 was our bread and butter so there was no question about what we had to do.
At that time, in line with a philosophy of dual sourcing, we were making the main fittings and the sliders for both the A340 and the A320. As a slider and a main fitting are two very different parts we were faced with long set-ups on most machines. With our beloved profilers making 6 parts at a time, we were caught in lot-mode at several steps in the process. Because set-ups were long, it was very tempting to continue with a lot-mode when the parts were available.
The volume increase forecast by our customer mainly concerned the A320 product. Messier-Dowty had decided to build a new plant in Mirabel, dedicated to the A320. All these changes gave us a real opportunity to think differently. We launched the idea of product lines: one for the main fitting and one for the slider. Machines were almost all dedicated to one product or the other. We calculated the "drumbeat" in order to determine the maximum length of the operation. It was around 10 hours. We bought 3 multi-axis milling machines in place of a profiler. Although these three new machines would perform the same operation, they were to be operated out of sequence so even though the total milling operation would still need about 30 hours, we could deliver one part every 10 hours to the next machining centre. The manufacturing layout was designed to ensure flow. So without knowing anything about Lean, we had begun to develop a plant in line with Lean methods.
Then September 11, 2001 came and everything changed for the aerospace industry. The balloon just blew up leaving us with a nice dream: three new milling machines already ordered, a new plant stillborn on the drawing table and a lot of disenchantment about the situation. There we were on the starting blocks, ready for competition and the race was cancelled.
Today it is one of the best things that happened to us. We did what we are best at, that is rolling up our sleeves and making good things from a negative situation. This is where we really started our Lean journey. We went back to the drawing board and asked how we could apply the new plant concept to the existing plant. Even though the forecasts were not as high as before September 2001, the demand was still going to end up being too high for our existing capacity. How could we swallow that?
We searched for help at this point as we were a little bit stuck. We met Larry Coté, President Lean Advisors Inc. (LEAD) and had a good discussion with him. This is when we discovered the value stream concept.
Creating the Value Stream: Current State and Future State Maps Identifying Our Product Families
Larry told us that the first step in establishing a Future State Map is to determine the product families and draw the value stream for each family. We decided to hire Lean Advisors (LEAD) to help us in this process. We arranged a working session on the subject in order to identify the product families.
Ha! Ha! This was our first struggle with the theory. If you look in the books, a product family is a group of products that go through the same or similar downstream or assembly steps or equipment (the definition of similar being 70% of the same work content).
The problem was that all our products had a similar manufacturing process and met this definition. So theoretically we would have only one product family. We thought that this would not bring us very far in our improvement process. So we had to think about a new definition, just for us.
First, we questioned the fact that sliders were included in the parts manufactured in-house. They were real disruption for us. Our Bidos plant was the one specialized in making sliders. This was their niche. Ours was the fittings. This is what we are good at. So we began to sell the idea to the corporate office and after a good marketing process, the deal was done. We increased our share of A320 fittings (dual sourcing program) and sent the sliders to Bidos.
Then, we split our products in 2 families: the A320 (A320 and A321main fittings) and the A340 (main fitting-300, main fitting -600, nose and center line). The justification behind this was that the A320 was a mature program with few quality issues, a higher volume and a great challenge to reduce cost. On the other hand, the A340 was more complicated, with more quality problems and a lower volume. Cost reduction, even though important for these products, was not as critical.
This became our definition of our product family (for the time being). So be very careful when you work on your product family definition. Keep the principles in mind but make sure what you select is logical and makes sense to your situation.
The Current State Map
Once you have established your product families and selected the one you will work on first, you have to map the current state of your value stream. The value stream is defined as all steps of both value added and non-value added activities required to bring the product from raw material to customer.
This exercise is essential because it ensures that people see the total flow process of the product including all the waste involved. As you draw your map, you will need actual data for activities like change over time, run time, downtime, rework time, etc. It's recommended that you measure that data as you do your Value Stream Mapping.
Once again our reality hit hard and forced us to be creative. We could not afford to wait weeks before having the current state completed. We decided to form a multi-skilled team and organize a workshop to establish our value stream. As the people we wanted to involve did not have a clue what Lean was, we asked Lean Advisors to organize a two-day Lean awareness session. This would get people familiar with Lean concepts such as waste and the value of 'pull' in production.
After that we split the job and worked with the operators to determine the data for our Current State Map. By asking different operators we were able to establish accurate data for the exercise. Again, we knew our problems were in the waiting time and in the different types of waste. To know if an operation was taking 2 hours or 2.1 hours was not as important as mapping the flow and identifying the different sources of waste.
After the awareness session, we had another to help us draw our Current and Future State maps. During this session, and over the weeks that followed, we drew the value stream on a big sheet of paper on the wall and calculated the time spent in adding value to the product. This time represented less than 10% of our total lead-time!
Although this figure is very common in manufacturing, it was astonishing for all people involved in the activity. We also put all the pieces in inventory on the map and we really 'saw' the number of parts that were just there sitting there, waiting to be processed.
This exercise took a lot of effort but it was extremely useful. In one diagram we could see all our opportunities for improvement. Then we started dreaming of what our process should look like a year from now.
The Future State Map
The theory says that the future state map should show where you want to be in a window of 6 to 9 months. Again this is the theory. Because we now had a big challenge in front of us involving the likelihood of major changes, we decided to open our future state window to 1 year. This would allow us to have enough time to make big changes in our process.
Our first change was to modify our organisational structure to reflect our product families. We appointed one operational director for each family. This was a major driver to implement the future state because it gives ownership of the product family to a person who can make operational decisions. We also reorganised all the production teams to reflect our value streams. We went to the extent of attaching, as much as possible, the operators to a value stream according to the skills needed in each product family.
We also took into consideration the personality of each operator in order to have a good fit into the chemistry of each team.
By doing that we were affecting each person directly so we had to do it properly and involve the people in the decisions.
The second step was to figure out how we could dedicate the machines as much as possible. This is where we decided to change a threat into an opportunity.
Remember we had ordered three machines for the new plant? When we tried to cancel the orders, we realized that the penalties would be very high. Having that in mind, we put together a business case to sell corporate the idea of buying the machines for the existing A320 line.
We told the executive committee that these machines would allow us to increase capacity while dramatically reducing both lead time and inventory as we implemented the concept of pull production. It worked and we got the deal! What a positive stimulation for everyone! Having said that, we had to walk the talk and do something to improve the process. We had to realize the Future State Map and do it quickly.
Lean Implementation: Realizing the Future State Map
Creating a Lean Structure
In order to move forward on our Lean journey, we needed people to help us. Lean is all about teamwork. So we had to put a Lean team and a Lean structure in place. Because our project was quite big and needed a lot of follow-up and energy, we decided to allocate full time people to the team. They had the task of establishing the Lean strategy and coordinating the Lean transformation process with the management team.
To do the follow-up and coordinate all the activities, we selected a Lean coordinator from the support team and, from the production group, we appointed a permanent change agent.
We also selected part time change agents from both production and support functions. The main strength of all those people was their willingness to change something and their positive attitude.
The aim of our Lean structure was to make sure Lean was fully integrated into our day-to-day life. So the first step the Lean team had to take was to make people aware of just what Lean is.
Building Lean Awareness
If you want to implement Lean, you need to make people aware of the tangible goals you want to achieve. If you don't do that, everything you will do will be seen as another flavor of the month, here today and gone tomorrow.
At that time, a corporate Lean initiative was launched with the aim to make Messier-Dowty a Lean enterprise. So, to bring people on board, we worked in coordination with the other Messier-Dowty sites to prepare a Lean awareness workshop. This workshop presents the basic concepts of Lean with key emphasis on waste and pull production. It includes a very simple simulation exercise that has had great success in helping people understand the improvement potential of Lean methods. After those sessions, it became clear to everybody that there was something there that could really make a difference to us. They may not have totally understood how it would work but they saw enough to be willing to learn more and help in the process.
At that point we could pass to the second step: stabilizing the process.
Stabilizing the Process: Selecting and Using the Lean Tools
Now it was time for us to implement the concept of Lean production. We did not know how and what but we knew it was the goal. We were, however, aware that pull production would reduce our inventory waste, mainly in the queue times. By doing that, we saw we might be at risk because of the process variations related to machine breakdowns and quality problems. We also realized that we had to dedicate machines as much as possible. In the Current State Map, we could clearly see that we were making more set-ups than parts!
Before implementing Kanban and pull production we had to reduce process variations. We had to stabilize the process. We also needed to build and maintain operator awareness of our Lean objectives. The best support tool to do that is 5S implementation.
5S Implementation
When done properly, 5S is a very rewarding tool for the people involved. 5S improves their work areas and the results can be seen immediately. When performed as a team exercise, it creates a real commitment to Lean implementation.
Again, in coordination with all the other sites, we put together a 5S training module. A typical 5S activity is performed through a three days workshop. It focused on one or two identical machines involving a minimum of two operators from this sector. The activity also involves 6 to 8 persons from different areas. Attendees also included 6 to 8 persons from different areas (operators from other production areas, people from support functions and often one director).
These multi-functional teams soon became a real strength in our 5S activities. The process gives people 'new eyes' in looking at their working area. It also allows people from completely different areas (for example, heat treatment, machine shop, assembly, etc.) to talk to each other and work together on the same objective.
We put together an aggressive calendar of 5S activities with audits, 5S boards, etc. These workshops were essential in changing the mindset of the operators. As we progressed through the shop, we made a lot of publicity around the results and we could feel the positive spirit replacing doubt and negativity.
From a mode of almost 'pushing' the activity we soon passed to having to turn away demands for the workshops! Almost every operator wanted to implement 5S in his or her area as soon as possible.
Although 5S is a very powerful tool to start your Lean journey, you have to use it very carefully. Make sure you adapt yourself to your people's capacity to change. Again, this takes a team approach done with real respect of each other. Otherwise you will waste your opportunities.
But 5S was just a step. In itself it does not bring significant long-term improvements to the process. We had to go further. One of our main issues was waste through machine breakdown. We decide to explore use of the Total Productive Maintenance TPM support tool.
Total Productive Maintenance (TPM)
We discovered that Total Productive Maintenance (TPM) was a journey in itself. But we had to start somewhere. So we decided to implement the foundation of the Total Productive Maintenance (TPM), autonomous maintenance or the operator's routine.
After the first workshops it became clear to us that 5S and autonomous maintenance were two complementary tools. After the first Total Productive Maintenance (TPM) workshop, we made it clear that completing a 5S on a machine was a prerequisite before going into this working area to implement autonomous maintenance.
Actually we found several machines with operator's routine already in place. Surprisingly, most of the operators were very enthusiastic about doing it. We found they also took on greater ownership of their machines in the process. Total Productive Maintenance (TPM) put the spotlight on our main issue, the maintenance organization.
Our maintenance people were far better at fire fighting than they were at planning ahead. They were good at dismantling a machine and getting it back up and running in 1 or 2 weeks but being proactive about problems wasn't their strength. When operators started to report small problems like oil leakage, broken gauges or any other small machine abnormalities, maintenance just shelved the reports saying they would look at any issues the next time the machine was down. Operators started to grumble that their proactive approach was useless and we were in danger of losing their all-important commitment.
So we had to work with our maintenance people to help them understand that we are serious about Total Productive Maintenance (TPM) and we really wanted to put that philosophy in place. Slowly but surely, with lots of communication and reinforcement, they started to come aboard with us.
Because we realized that Total Productive Maintenance (TPM) was a key to our future success in implementing pull production, we decided to hire a consultant to help us in making a diagnostic of the actual situation and establish an action plan for the next few years. We really wanted to be a world-class plant for maintenance and radically reduce our machine breakdowns.
This activity is now in progress and, again, we are taking a multifunctional team approach. The action plan should be ready in September of 2003.
SMED
In our Value Stream Mapping, there were some machines that were not dedicated and were affected by long set-ups. We concluded that we needed to learn another tool, the SMED (Single Machine Exchange of Die. Also known as Quick Changeover).
One of the machines we targeted was the Deep Hole Borer. We have 2 machines like that. Every part has to go through each machine at different steps of the process so each machine sees the complete mix of products. Some set-ups were very long. We had to plan a complete shift for transition from one product to another. Because of that, we produced parts in lots. That situation gave us two good reasons to perform a SMED exercise: decrease the time lost in changeover, and get rid of the lot production system that resulted in long queue times.
We organized a SMED workshop, again with a multifunctional team. After making a video of a complete set-up and analyzing it step by step, we started a brain storming session. After several hours of hard work, people identified ways we could dedicate almost every machine to one of our major products and reduce the change over to a very simple adjustment. From an actual change over time of 8 hours, we ended at less than an hour. The result was astonishing!
Implementation was not an easy task as we were faced with several technical issues. However, with the appropriate investment, we were able to go forward. We gained in production time and, almost as importantly, we removed the potential roadblocks to our Future State pull production strategy.
Quality Improvements
While we did not face dramatic needs in terms of quality issues, we did have our share of quality problems with our parts. Often, these issues ended up in deviation-to-spec requests to our customer. Processing time for those deviations could vary between 10 to 30 days (or more if the problem was very serious). The defective part had to be removed from the production flow. Continuing this situation would have a major negative impact once in a pull production environment.
The solution was to work on our process to prevent those deviations from occurring. We started to follow our deviations closely using QOS system (Quality Operating Sheet). We organised quality working groups by product and involved people from quality, manufacturing engineering, as well as the operators. Their mandate was to investigate the deviations, find the root causes and come up with permanent solutions. These groups were loosely structured and they did not necessarily use standard problem solving methodology. However, just by taking the time to analyse the deviations together, we saw a significant improvement in the number of parts with quality issues.
Problem solving methodology is still something we need to work on if we want to continue to improve our quality results and stabilize our production output.
There are several other tools we know we have to put in place if we want to maximize our process stability. One of them is standardized work. These are our opportunities for the future.
Pull Production
One of the big steps in a Lean journey is to implement production of one piece-flow in a pull mode. In order to implement that strategy, the theory says that you have to start at the nearest point to your customer. For once, we were lucky as this point is the assembly area where we have no equipment reliability problems and no quality issues. The process is quite stable. So we decided to implement a pull system there.
Good luck! This is when we started to struggle trying to understand the different concepts of pull, FIFO, Kanban, supermarket, cellular manufacturing, and line balancing. It seemed like a nightmare! We decided to call on Lean Advisors to help us in understanding how these concepts could work together.
Again, the theory was not really in line with our reality. Books always talk about small pieces, small operations, movable equipment, repetitive work, etc. We had a hard time figuring out how can this applied to us. Between Lean Advisors and ourselves, we realized that cellular manufacturing is not easily applicable to our process but some elements were still usable. We decided to play the game and make the study for all sub-assembly processes.
We split the process into three cells: bushing area, paint shop, assembly. The bushing area and the paint shop are involved in all products while assembly is dedicated to A340 main strut.
We started to monitor the tasks involved in the process in these 3 areas. Again we involved the operators because this type of monitoring can be very touchy. By looking at the results, we concluded that the bushing area was a good candidate for implementing the cellular manufacturing concept.
We also decided to redesign the layout of the three areas. Our 'spaghetti diagrams' showed an important potential for improvement in terms of efficiency. It was a good time because we had to buy a new paint booth as well as a new cleaning room because of health and safety issues. The new design would allow us to optimize the flow and implement cellular manufacturing in the bushing area.
We would also be able to save 5000 square feet of floor space that could potentially be used for two new machines. The target date to implement this new layout in the paint shop (first phase of the project) will be December 2003 and the entire project should be completed by June 2004.
In the mean time, we decided to implement a Kanban system in the special processes and assembly areas. And this is where we actually are today. Even though it seems simple, a lot of work is involved in this Kanban implementation because it will be the first Kanban and we don't yet have much knowledge about it. But we're not afraid of challenges, we'll just jump into it together!
As soon as the three machines are operational, we will put in place our Future State Map for the machining process. Our objective is the implementation of a complete pull system for the A320, from raw material to the finished assembly. We plan to do it in steps. There will be supermarkets at some specific places in the process while we continue to work on process stabilisation. This means a lot of work but with the willingness and the energy of all people in the shop, from the senior management to the operators, we should more than achieve our results target.
The Keys to Success in a Lean Journey
People are the number one key to success! By demonstrating a commitment and a willingness to change things, management should convince all the employees to work as a team in starting a Lean journey.
Depending on the shop history and the level of trust the employees have in the management team, this could be more or less difficult. But it is the first step if you really want to accomplish something that will last.
Nothing is easy with Lean. It is also a journey that will never end. It will take a lot of sweat and give you a lot of headaches. But it is continually self-rewarding when you start to see all the improvements and the accomplishments achieved with all the positive energy it produces.
After a year and a half of struggling, we discovered that there are some basic steps that a company must follow in successfully implementing Lean.
» The management team must have a vision and a strategy for Lean and should demonstrate their commitment to people at every level of the company.
» You need to work on your organisational structure in order to reduce the number of decision levels.
» At the same time, you have to work on the culture and the working environment to make employees feel more responsible for their work. This is what we call people empowerment.
» Determine your product families and draw your Current State Value Stream Map. Then draw your Future State Map.
» By using the Lean support tools properly and in the right sequence (5S, TPM, SMED, Standard work, problem solving, etc.) stabilize your processes.
» Once your processes are more stable, implement the pull production concept starting at the point nearest to your customer. Then extend the pull progressively upstream in the respective processes.
» Always have your customer's expectations in mind and work to improve quality, cost, and prompt delivery.
By doing this, you should see positive changes in the spirit of your employees and in your operational results. But don't forget, Lean is a long-term investment. If you are committed, patient and persevering, significant and sustainable rewards will be there.