Lean Manufacturing and Environment
- Lean Efforts
- 777 Floor Grid Component Delivery Improvements
- 747 Line Side Supply and Simplified Ordering System
- Chemical Point of Use Stations
- 767 & 747 Wing Seal Moving Lines
- 747 Horizontal Stabilizer Project
Boeing is implementing Lean projects in various ways throughout its Everett Plant. The Company created an overall Lean Group to assist in the development and implementation of Lean initiatives throughout the plant. Programs invite the Group to participate in specific Lean projects if desired. The different airplane programs and organizations have also created their own Lean offices to focus specifically on Lean efforts within the particular program. For example, the 777 program has developed its own office, Critical Process Reengineering (CPR), to look for opportunities within the 777 line.
Throughout the Everett plant, Lean initiatives have yielded measurable results. Larger efforts, like some of those described below, have resulted in substantial resource productivity gains and savings. Smaller efforts have also produced significant benefits. For example, the development and implementation of an alodine pen to be used prior to primer touch up, has reduced hazardous waste generation by approximately 36, 55-gallon drums per year. As part of a small tool recycling and reconditioning program, the 777 Wing Majors shop is recycling plastic spatulas used to apply sealant, reducing hazardous waste generation by approximately 90 percent (only the scraped sealant residue and velcro pad are disposed of, not the spatula itself).
To illustrate in greater detail the affect of Lean Manufacturing efforts at the Everett plant, five Lean projects were selected for closer examination. The initiatives selected and detailed below are the 777 Floor Grid Component Delivery Process, the 747 Line Side Supply and Simplified Ordering System, Chemical Point of Use Stations, 767 & 747 Wing Seal Moving Lines, and the 747 Horizontal Stabilizer project. These efforts are at various stages of implementation and the final effort, the 747 Horizontal Stabilizer Project has been put on hold due to technical and regulatory constraints.
Boeing, as part of its overall Lean efforts, created a Lean Office to support the Twin Aisle Program (747s, 767s, and 777s). The 777 Line also formed its own group, CPR, to analyze current practices and identify potential Lean opportunities within the 777 program. In identifying potential opportunities, 777 operations were examined in total, providing a broader perspective of the overall program. In taking this more global approach, CPR identified as cost reduction opportunities the shipping processes used for seat tracks and floor beams. Boeing produces the parts in Wichita, Kansas and Tulsa, Oklahoma and then ships them to the Everett plant in Washington State.
CPR held a "Link the Flow" workshop to develop a Lean Vision for the shipping of 777 floor grid components. Workshop participants focused on shortening the overall value chain and developed a vision of the ideal shipping process. The participants also developed an interim vision, which serves as a midpoint target in the process of continually improving the shipping system.
Previously, Boeing delivered 777 seat tracks from Wichita and Tulsa to the Boeing Everett plant by truck. The parts were unloaded at Receiving and Inspection and then delivered to the factory for assembly. Boeing shipped 777 floor beams by truck from Tulsa to Kansas City then loaded them onto a train for shipment to Seattle via rail. From Seattle, a truck transported the floor beams to Receiving and Inspection at the Everett plant. Eventually the parts were brought to the factory for production purposes.
The Workshop resulted in a new delivery method for 777 floor grid components. Trucks now transport seat tracks from Wichita to Tulsa, pick up the floor beams then, carrying complete ship sets, travel directly to Everett and deliver the parts directly to the factory for use. Receiving and inspection processes are conducted at the plant. The redesigned shipping process allows a single truck to deliver a shipset of floor grid components directly to their point of use.
As a result of the new shipping process, Boeing has realized the following resource productivity gains:
- Multiple transfers, rail travel, and truck travel to the rail heads have been completely eliminated. Trucks no longer run empty from Kansas City to Tulsa because shipping by rail has been removed from the process.
- Eight days of travel and three days of receiving and inspection have been eliminated. C Approximately $7,900 has been saved per shipset or $396,000 in annual transportation costs.
- Floor grid inventory has been reduced by 25 percent. Components are now shipped directly to the factory when they are needed, reducing the number of overall ship sets required in the delivery pipeline.
- Each ship set uses 50 percent less transportation (and associated energy and maintenance). Previously, Boeing trucked half of one airplane's worth of floor grids to Everett and trucked and then shipped by train the other half to Seattle; Boeing now ships one airplane's worth of floor grids in one truck from suppliers in Tulsa and Wichita directly to the Boeing factory in Everett.
- Overall handling of materials has been reduced, yielding a reduction in forklift use. Decreased forklift operation represents savings associated with fuel, maintenance, and driver time.
- Also, in response to Boeing's new shipping process, the floor grid component suppliers have adjusted their manufacturing schedules so that they do not produce and accumulate excess inventory at their production sites.
The Wing Responsibility Center, using a specially-chartered team working with the Parts Control Organization, (the organization responsible for material handling and inventory control across the Boeing Commercial Airplane Group), developed the 747 Line Side Supply and Simplified Ordering System. This 747 Lean project focuses on improving the inventory and supply chain systems for fiberglass panels comprising wing trailing edge areas.
Under the previous inventory and supply system, a supplier in Kent delivered bulk shipments of panels to the Everett plant. Boeing temporarily stored the panels in a factory parts control area before delivering them to the factory floor for installation. The fiberglass panels are fragile, requiring each to have cardboard wrapping, with approximately 60 percent having plastic bubble wrap inside the cardboard. Boeing discarded the cardboard when unwrapping the panels in the factory parts control area and the bubble wrap when a mechanic installed the panel on an airplane.
To provide better inventory control and decrease damage, the Wing Responsibility Center is implementing a "kanban" cart system. This system is built around constructing and introducing custom carts which the vendor in Kent will use to transport the panels directly to the 747 Wing Majors area point of installation. To control the amount of inventory shipped, one set of carts is capable of holding only one ship set of panels. The Wing Responsibility Center's return of an empty cart signals the vendor that Boeing requires another ship set.
The transportation carts are also designed to reduce packaging waste. Carts have restraining straps and are segregated into padded compartments so that individual fiberglass panels require no packaging. Carts are also more ergonomically correct to reduce worker injury.
When fully implemented, Boeing anticipates the following resource productivity gains.
- Fiberglass panel inventory will be reduced from 14 ship sets to 4. C Rework due to handling damage will be virtually eliminated. (Previously shipping and storing handling damage required fiberglass rework of a significant number of the 140 panels in a ship set.)
- Approximately 350 cubic feet of cardboard and bubble wrap packaging will be eliminated per wing ship set.
- Parts and mechanics travel will be reduced because parts will be shipped directly to the point of use in the wing assembly area.
Boeing's Safety, Health, and Environmental Affairs organization (SHEA) developed the Point of Use system for chemical materials. Generally, point of use efforts enable the storage of materials where the production process utilizes them. Boeing's key objectives for point of use chemical stations are reductions in mechanic travel and better control of the supply, use, and distribution of hazardous materials. Ultimately, reduced mechanic travel time was the primary financial driver for this change. Currently Everett has over 120 point of use stations.
Prior to implementing the point of use stations, several chemical disbursement centers, known as chemical cribs, distributed the paints, sealants, solvents, and other chemical materials required for airplane assembly. Mechanics were required to pick up new materials from, and return unused and waste materials to, cribs. This entailed frequent travel over substantial distances.
The new stations are self-help areas that allow mechanics to pick up materials and return waste at the point of use. A Hazardous Material worker visits the point of use stations at least twice a shift to check supplies, pick up waste, and resupply material for the specific applications occurring within the station area. Boeing controls the amount of chemical inventory and waste on the floor by using minimum/maximum quantities, right-sizing containers, (holding only the necessary amount of material required for a specific application), and limiting each station's quantity of containers.
Boeing tracks the point of use station materials by bar code to determine what types and quantities each factory location uses. Boeing uses the tracking to prepare a 30 day reduction report. The report analyzes the amount and type of chemicals used and helps to determine how much inventory to carry where in the system. If a particular location does not use a specific product regularly, Boeing lowers the product's maximum amount at the station. Boeing expects to track dry goods for chemical applications in the future to assist in overall waste reduction.
Each point of use station also utilizes small, (less than 55 gallons) segregated cans for waste materials. Shops segregate their own waste, and Boeing color codes chemical products and the waste stream to reduce the possibility of mistakes. Each also has a reuse section. If material is leftover after an application, mechanics can place the excess material back at the station for future use.
Implementation of the Point of Use Stations has yielded the following resource productivity gains:
- Chemical use per airplane has been reduced by approximately 11.6 percent
- The amount of chemicals on the shop floor has been reduced by 23 percent
- Overall material waste has been reduced due to the use of right-sized containers and easier mechanic access to materials; and C mechanic travel has been reduced by 56 percent, representing an average of 567 fewer trips and 95 hours of less travel per day.
The Everett Wing Responsibility Center has been engaged in efforts to establish several moving production lines. As part of that effort, the Center examined the 767 and 747 wing sealing processes. Operations within those processes include exterior sealing, in-tank sealing, pressure testing, and painting applications. The Center conducts these large scale chemical processes in a separate, dedicated factory building with full environmental controls, including specialized air cleaning and water collection systems. Cranes lift the large wing assemblies to the building from various areas in the factory where assembly takes place.
Previous operations had each 767 and 747 wing craned into one of 12 different positions in the building for internal and external sealing and pressure testing. Subsequently, cranes moved each wing to three additional positions, each corresponding to separate processes: spar (edge) painting, large surface painting in vertical paint booths, and a final job pickup position. As many as three sets of 767 and 747 wings could be in work at any given time. Chemicals were spread among all 12 positions, and varied depending upon the work being done in each position.
As part its Lean efforts, the Wing Responsibility Center has reconfigured these sealing operations into two moving lines, for 767 and 747 wings. This process results in no more than four wings receiving work at a time: one 767 and 747 wing on the moving lines, and one of each in the vertical paint booth.
The moving lines, established in April 2000, have four or five workstations, depending on airplane model, on each side of the wing. At these fixed workstations, mechanics perform exterior sealing and corrosion sealing as the wings move slowly by on two drive units. Each workstation is height-adjustable to improve ergonomics and has a point of use chemical station containing the materials required for each processing step. Waste is deposited and collected at the point of use stations.
The Wing Responsibility Center has short-term plans to add in-tank sealing, exterior masking, and painting to the line activities. Long-range plans include the possibility of adding leak testing, plumbing installation, and the large-scale painting currently done in the special paint booths.
The moving seal lines, as currently configured, have achieved the following benefits:
- Flow days have been reduced from 13 to 6 for the 747 and from 12 to 6 for the 767.
- Crane moves, required to move the assembled wing throughout the factory, have been reduced from 7 to 5. (Limiting crane moves is a priority for Boeing because the complexities of crane moves for large aircraft parts often cause delays in the overall production process.)
- The point of use stations, affixed to work platforms, allow for better chemical material inventory control, reducing the amount of both chemical inventory and waste. Boeing is also exploring the possibility of developing a process that would allow employees to mix seal at the gun itself, so mixed sealant in freezers would no longer be required. This would reduce the waste generated by sealant inventory that is not used within a specified period of time.
- Fixed position sealing requires less sealant, thereby producing less hazardous waste. In addition, because there is less inventory on the floor, (i.e., 4 wings versus 12), there will be less overall chemical inventory spread throughout the building.
- There have also been significant gains in available floor space, which may be used in the future to accommodate additional sealing and mechanical assembly processes.
WRC's initial design efforts indicated that the ideal configuration for the moving lines would have been two parallel lines (one each for the 767 and 747), thus optimizing building space. Although the building currently has full environmental controls, Boeing determined that this ideal configuration (from a production process perspective) would require new building and environmental permitting activities. Because implementation time was critical to the viability of this project, the anticipated delays of conducting these activities, and uncertainties associated with them, convinced WRC to accept a less than ideal configuration; aligning the moving lines to utilize existing ventilation systems and environmental controls.
Technical constraints have also influenced the development of the moving lines. Specifically, the cure time of sealants and paints dictate the flow time of the moving line. The flow cannot be too rapid because paints and sealants require specific curing times. In an effort to address this issue, the Wing Responsibility Center is currently exploring the existence of new technologies such as faster curing sealant and accelerated paint curing.
The Everett Wing Responsibility Center also has examined the possibility of establishing a moving line for the 747 Horizontal Stabilizer. Like the Wing Seal process, the Horizontal Stabilizer production consists of both chemical and assembly processes. Unlike the Wing Seal line, however, the WRC had interest in locating the entire horizontal stabilizer process line on the main factory floor. The WRC currently joins the 747 horizontal stabilizer in the main factory, then transfers it to an environmentally controlled building, roughly ½ mile away, for sealing, painting, and seal testing. As a fuel cell, the 747 horizontal stabilizer must receive a seal test. The current test entails filling the cell with ammonia to detect any leaks. Additional seal work and paint applications are also conducted in this facility. The WRC then moves the horizontal stabilizer back to the main factory for anti-corrosion applications and final assembly. (The anticorrosive application is conducted within temporary confinement walls with a ventilator.)
The Wing Responsibility Center has envisioned using small booths or other technologies to replace large scale chemical and painting processes and integrating these processes into a continuous manufacturing cell-based production flow, thus eliminating multiple crane-dependent stabilizer moves in and out of specialized facilities. This would create a one-piece, pull-production system capable of all stabilizer process steps: assembly, sealing, painting, leak testing, and paint and corrosive inhibitor compound (CIC) applications. WRC would depend on smaller, right-sized, moveable equipment to support this redesigned process.
The Wing Responsibility Center anticipates the following resource productivity gains from implementation of the 747 horizontal stabilizer moving line
- A reduction from 16 to 4 flow days.
- Elimination of 23 overhead crane moves, reducing the total number from 31 to 8.
- Space requirements reduced from 29,600 to 14,800 square feet.
- Significant energy savings due to the reduction in crane moves and space required for production.
- An approximate 10-20 percent reduction in paint overspray and solvents required for component applications due to the use of small, in-line chemical operations.
Regulatory and technological constraints (and the time required to develop possible solutions) has caused WRC to place the entire 747 Horizontal Stabilizer project on hold. WRC directed manufacturing, engineering, and technical resources toward overcoming some of these obstacles, however the work was expensive and time consuming. Approaches explored to overcome some of these constraints included changing the technology associated with certain processes, eliminating the processes, or substituting another, less hazardous process.
In particular, the seal test and painting applications have presented significant obstacles. WRC currently conducts the seal test (which uses ammonia, a compound strictly regulated by OSHA, fire code, and environmental regulatory requirements) under only highly constrained conditions. These strict requirements dictate the limited conditions under which the seal test can occur. In response, Boeing is exploring alternative substances (such as helium) and methods for conducting the seal test. If helium proves viable, WRC would completely eliminate ammonia from the process.
Spray painting/coating operations also presented various obstacles. To move painting processes onto the main factory floor, the Wing Responsibility Center began developing self-contained, moveable, right-sized painting units. The Center examined smaller units because it viewed the costs of moving "as is" painting operations onto the floor as too great.
As WRC explored various technological approaches to small scale, in-line mobile equipment, the number and variety of requirements associated with moving the spray painting/coating operations onto the factory floor became apparent. Requirements included those associated with the Building and Fire Code, OSHA, and the Clean Air Act. Although no single requirement or regulation proved to be an impediment that could not be overcome, the combination of requirements was overwhelming in light of the time and resources WRC could make available to the project. WRC also perceived significant uncertainty as to whether any self-contained, moveable, right-sized painting unit could receive a permit under the Clean Air Act. Because of the cost, time, and uncertainty associated with the identified regulatory requirements, WRC discontinued further technological development efforts and placed Horizontal Stabilizer moving line development entirely on hold.