Automotive Vehicle Assembly Processes and Operations Management

Name: Automotive Vehicle Assembly Processes and Operations Management
Brand: SAE International
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He Tang(Author)

SAE International (Publisher)

1st Edition

Published on 30. January 2017

296 pages

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Content

Intro
Preface
I.1 Approach
I.2 Organization and Content
Acknowledgement
Automotive Industry and Competition
1.1 Automotive Market Overview
1.1.1 Global Automotive Manufacturing
1.1.1.1 Global Market by Region: Figure 1.1 shows the vehicle sales in major countries [1-4]. The characteristics of the major countries and regions are discussed below.
1.1.1.2 Major Automakers: There are more than 100 automakers in the world. Table 1.1 lists the top twenty automakers worldwide based on their production volumes of passenger cars in 2014 [1-6]. The top ten automakers produced around 72.5% of passenger car
1.1.2 Characteristics of Automotive Market
1.1.3 Dimensions of Market Competition
1.1.3.1 Four Market Competitive Attributes: The automotive market can be viewed in four competitive attributes: time to market, price, quality, and variety. The first, time to market, is a key success factor that is about how quickly a new model can be av
1.1.3.2 Five-Force Model: For studying industry competition, Michael Porter's five-force model [1-12] is often used. Porter's five forces are (also refer to Figure 1.3) as follows: 1) threat of new entrants, 2) bargaining power of buyers, 3) bargaining po
1.1.3.3 Manufacturing Capacity: Production capacity is a major competition factor. The capacity of an automaker is normally measured as two-shift production in a plant for mass production models. As a high volume production may offset the development cost
1.2 Manufacturing Competition and Assessment
1.2.1 Automotive Industry Competition
1.2.1.1 Quality and J.D. Power Indexes: J.D. Power indexes rest on public surveys. Therefore, the indexes are another influential indication of vehicle quality for the customers and automaker management. J.D. Power indexes address the different aspects of
1.2.1.2 Labor Utilization Efficiency: Automobile manufacturing is a labor-intensive business. Another indication of manufacturing competition is workforce productivity. One of the measures utilized is how many working hours are spent to build a vehicle, o
1.2.2 Automaker Performance Assessment
1.2.2.1 Total Company Performance: Total company performance (TCP), developed by McKinsey, is an overall evaluation for automakers. The TCP considers many dimensions on automakers' performance, based on publically available information. The TCP assesses a
1.2.2.2 Consumer Reports Magazine: Customers often use data from third parties as reliable references. Consumer Reports Magazine (CR), having over seven million subscribers [1-19], is one of those references. CR developed an evaluation scoring system for
1.2.2.3 Other Indicators: Another indication is based on analyzing inputs from customer interviews. The American customer satisfaction index (ACSI), for example, directly represents customer loyalty to a particular product or brand, by measuring the custo
1.3 Business Strategy Considerations
1.3.1 Strategy Basics
1.3.1.1 Three-Level Strategy: Strategy is a general term. It refers to the basic long-term goals of an enterprise or a division. For a corporation, its strategy is to answer what business it should be in and what it should do to gain competitive advantage
1.3.1.2 Generic Strategies: There are two basic types of competition in the business world: 1) cost leadership (or called low cost) and 2) product (and/or service) differentiation. According to the two types of competition, automakers may have different c
1.3.1.3 Characteristics of Strategy: In general, the fundamental factors of a successful corporate strategy are a good understanding of the market requirements, trend, and corporation competitive position in terms of capabilities. The key point is how to
1.3.2 Discussion on Automakers' Strategy
1.3.2.1 Strategies for Automakers: The low-cost strategy works to attract many vehicle customers who incur low switching costs. This explains why the price war in the automotive market is intensive, pushing automakers to often use heavy incentives to attr
1.3.2.2 Corporate Strategy Case Studies: Ford has been a top automaker for a long time. However, its profit has been up and down a few times in the last 15 years. It had financial difficulty in 2002 through 2003, large loss in 2006, and again in 2008, as
1.3.2.3 Manufacturing Strategies: Generally, manufacturing strategies are balanced objectives of cost, quality, delivery, and flexibility. The key contributing factors to these objectives include manufacturing systems and equipment development, process pl
1.4 Exercises
1.4.1 Review Questions
1.4.2 Research Topics
1.5 References
Automotive Manufacturing Operations
2.1 Overall Automotive Manufacturing
2.1.1 Introduction to Vehicle Assembly Plants
2.1.2 Flows in Automotive Manufacturing
2.1.3 Process Flows of Vehicle Assembly
2.2 Vehicle Assembly Operations
2.2.1 Body (Weld) Framing
2.2.1.1 Overview of Vehicle Body Assembly: Vehicle body framing is the first main operation of the vehicle assembly. The aim of body framing is to precisely join all body parts together. The main manufacturing process in a body shop is welding. Hence, the
2.2.1.2 Process Flow of Body Assembly: The process flow of a body shop largely depends on the body architectures. The most common architecture is called unibody, which is the short term of unitized body. In such an architecture, a vehicle body is framed a
2.2.2 Paint Operation
2.2.2.1 Overall Painting Flow: The second major operation of vehicle assembly is body painting. A paint shop is 800,000 to 900,000 ft2 (74,322 to 83,613 m2). Vehicle bodies travel about four miles (6.44 km) on multiple segments of conveyor systems through
2.2.2.2 Main Painting Processes: The first stage in the paint process is phosphate treatment. The vehicle bodies arriving from the body shop need be cleaned to remove stamping compounds, oils, dirt, and other contaminants. The cleaning begins with deluge
2.2.3 General Assembly
2.2.3.1 Process Flow of General Assembly: GA is the last major operation for vehicle assembly. In a GA shop, many components and subassemblies (modules) are installed onto a painted body to complete a vehicle. Accordingly, GA is often subgrouped into trim
2.2.3.2 General Assembly Operations: The operations in a GA shop vary in terms of complexity and time. Some operations are simple. For example, various labels are applied, such as air bag warning labels, emission label, fuel label, occupant classification
2.2.3.3 Characteristics of General Assembly: The assembly operations can be either automatic or manual. For example, front and rear glass installation is typically performed by robots. Other relatively simple operations, such as loading batteries, front s
2.3 Automotive Part Manufacturing
2.3.1 Sheet Metal Stamping
2.3.1.1 Overall Stamping Operation: Sheet metal forming provides the parts for vehicle body assembly. Coils and flat blanks of sheet metal are introduced in press shops where the forms of parts for the contours of vehicle are created. It is a common pract
2.3.1.2 Typical Stamping Processes: The stamping operations start from blanking as the sheet metals are supplied either in coils or as flat sheets. The purpose of blanking is to cut the shape of blanks based on the final part dimensions and subsequent for
2.3.1.3 Hydroforming Process: A relatively new vehicle body architecture is called space frame, which uses a tubular structure frame for the load bearing of a vehicle. The space frame architecture is increasingly used for vehicle body structures recently.
2.3.2 Powertrain Manufacturing
2.4 Distinctiveness of Automotive Manufacturing
2.4.1 System Perspective on Automotive Manufacturing
2.4.1.1 Viewpoint of Conversion: In terms of the conversion, the entire automotive manufacturing system converts raw materials into customer vehicles, as shown in Figure 2.21. At the system level, the aim of a manufacturing system can be defined as the de
2.4.1.2 Functional Viewpoint: The manufacturing systems may also be viewed as a network of various well-organized value-added activities and functions to the ultimate customers. Thus, the manufacturing adds a margin of value to both the automaker and its
2.4.1.3 Performance Viewpoint: A simple example to view manufacturing with a system perspective may be to evaluate production performance. For vehicle assembly lines, their production speed is fixed. However, production output may be changed by adjusting
2.4.1.4 Subsystems of Vehicle Assembly: A vehicle assembly plant is a huge system. It includes many assembly lines and various types of equipment and processes. As a complex system, it has multiple layers, called subsystems. It is a common practice that a
2.4.2 Characteristics of Vehicle Manufacturing
2.4.2.1 Types of Manufacturing Processes: In general, there are four basic types of manufacturing processes:
2.4.2.2 Discussion of Vehicle Manufacturing Processes: In addition, vehicle assembly operations appear unique. Their inputs, outputs, types of process, product variety, and automation levels are listed in Table 2.8, where the levels of operation automatio
2.5 Exercises
2.5.1 Review Questions
2.5.2 Research Topics
2.6 References
Joining Processes for Body Assembly
3.1 Resistance Spot Welding
3.1.1 RSW Principle
3.1.2 Characteristics of RSW Process
3.1.2.1 Process Parameters of RSW: The three major process parameters of RSW are electrical current, electrode force, and welding time. The roles of electrical current and time in RSW process can be explained by (3.1). The force ensures the closed electri
3.1.2.2 Steel and Aluminum Welding: Along the trend of vehicle weight reduction, more ultrahigh strength steel (UHSS) and aluminum are used. A challenge of UHSS welding is that the welds may fail in a unique mode called interfacial fracture (IF). The adva
3.1.2.3 Controls of Current and Force: Varying electrical current and electrode force profiles during welding cycles is a new approach of welding control. Electrical current can be changed to several pulses, shown in the left chart of Figure 3.6. The key
3.1.3 RSW Equipment
3.1.3.1 Weld Guns: The main components of an RSW gun include gun body structure, driving mechanism, controller, and transformer (refer to Figure 3.7). The gun body configurations vary in terms of size and shape for welding access to the designated areas.
3.1.3.2 Electrode Caps: The electrode caps vary widely (shape of nose), materials, face diameter (n), as well as mounting connections. Some of the common types are shown in Figure 3.9. The commonly used face diameters of electrode caps are 1/2 in (12.7 mm
3.1.3.3 Correction of Cap Wear: Because of their wear, electrode caps need to be changed periodically. Between the cap replacements, the welding current needs to increase after a certain number of welds that are made in order to keep the current density a
3.2 Laser Beam Welding
3.2.1 Principle and Characteristics of LBW
3.2.1.1 Principle of Laser Welding: The main types of industrial lasers used for vehicle body welding are carbon dioxide (CO2) and neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers. Both lasers operate in the infrared region of electromagnetic radia
3.2.1.2 Characteristics of Laser Welding: The general characteristics of laser sources are displayed in Table 3.3 [3-10]. The laser output power determines welding speed and weld penetration. CO2 laser output can be up to 60 kW with good beam quality. Hen
3.2.1.3 Advantages of Laser Welding: Compared with other welding processes, LBW has many advantages. It is very capable of welding deep and narrow joints, which is important for body assemblies with thick metal, extrusions, and castings. Its single-sided
3.2.2 Challenges to LBW and Solutions
3.2.2.1 Initial Investment: It was optimistically predicted that LBW would replace RSW. However, the initial capital investment required for LBW seems to be a major obstacle. To meet the requirements of better part fit and more accurate part positioning,
3.2.2.2 Welding Zinc-Coated Steels: Most of vehicle body sheet panels are made of the zinc-coated (galvanized or galvannealed) steel sheets. During LBW, zinc vaporizes at a lower temperature (906 °C) than the melting point of steel (approximately 1500 °C)
3.2.2.3 Advancements of LBW: As a new welding technology, the laser source and process keep advancing. For example, the direct diode laser is a new type of laser source. Its advantages include high efficiency, long service intervals, lightweight, and comp
3.3 Other Types of Welding
3.3.1 Arc Welding
3.3.1.1 Principles of Arc Welding: Arc welding is a process in which an electric arc is formed between a consumable wire electrode and the parts. The arc heats the parts, causing them to melt, and joins them together, as shown in Figure 3.17. Among severa
3.3.1.2 Characteristics of Arc Welding: The arc welding process is sensitive to the part fit. With a filler material, that is, welding wire, arc welding can fill the small gap between the parts to be welded, particularly for experienced manual welding. Ho
3.3.2 Projection and Draw Arc Welding
3.3.2.1 Projection Stud Welding: Fasteners are widely used for the installation of parts, units, and modules in vehicle general assembly. The fasteners, in the form of screws or nuts, are planted on the surfaces of a vehicle body. There are several hundre
3.3.2.2 Drawn Arc Stud Welding: Drawn-arc stud welding, in principle, is a type of arc welding. A threaded stud serves as an electrode for the arc welding. In the process, the electrical arc is generated by a push-pull-push movement of a stud, described b
3.3.3 Friction Stir Welding
3.3.4 Impact Welding
3.4 Mechanical Joining and Bonding
3.4.1 Self-Piercing Riveting
3.4.2 Clinching
3.4.3 Adhesive Bonding
3.4.3.1 Applications of Adhesive Bonding: Adhesive bonding is increasingly applied in vehicle body assembly because of improved BIW structural stiffness and crash resistance.
3.4.3.2 Design Considerations for Bonding Joints: In general, the adhesive applications should meet the following requirements:
3.4.3.3 Process Considerations for Bonding Joints: A key consideration in process planning is that the RSW or mechanical join should be immediately applied after the adhesive application. If adhesive application is with laser welding, an additional fixtur
3.5 Selection of Joining Processes
3.5.1 Advancement Trends in Joining
3.5.2 Overall Comparison
3.5.3 Selection Considerations
3.6 Exercises
3.6.1 Review Questions
3.6.2 Research Topics
3.6.3 Analysis Problems
3.7 References
Vehicle Paint Processes
4.1 Surface Treatments and Electrocoating
4.1.1 Clean and Phosphate Processes
4.1.1.1 Process Flow of Phosphate: Vehicle cleaning and phosphate process is the first major process in a paint shop. Cleaning and phosphate serve different purposes, but are normally designed into a single line. To ensure the readiness for subsequent pho
4.1.1.2 Process Parameters of Phosphate: The process parameters of the phosphate chemical process should be monitored and maintained in real time. They include the pH value, concentrations of chemical agents, temperature, and time. The entire phosphate pr
4.1.2 Electrocoating
4.1.2.1 Introduction to Electrocoat: The full name of E-coat is electrodeposition coating that is a primer coating for both performance and economic benefits. In terms of performance, the E-coat adds additional corrosion protection and adhesion for conseq
4.1.2.2 Principle of Electrodeposition: The E-coat process is based on the principle of electrodeposition. In this process, electric voltage is created between anode and cathode electrodes by a DC power supply. There are many anodes designed and placed in
4.1.2.3 Process Parameters of E-Coat: There are five main parameters for the E-coat process, listed and briefly explained in Table 4.4. The process parameters in an E-coat tank are paint material dependent and should be monitored and maintained. The appli
4.1.2.4 Challenges to E-Coat: The lightweighting trends of vehicles also affect and challenge the E-coat process. There are two main factors: one is different and multimaterials using for vehicle bodies, the other is new joining technology involving dissi
4.1.3 Phosphate and E-Coat Facilities
4.1.3.1 Vehicle Conveyance: The conventional body movement in the immersion tank is known as translational. Body rotation can be added to the basic translation. In other words, a car body dives into the tank, has a translational movement or with rotation
4.1.3.2 Material Feed and Filtration: The phosphate and E-coat operations are continuously running around clock. Thus, there are high requirements for the tanks, not only on structure and construction but also on chemical resistance and electrical insulat
4.1.3.3 E-Coat Anodes and Anolyte System: For E-coat process efficiency, such as better E-coat throwing power, the immersion process is normally separated into two zones in a tank. The electrical voltage in the first zone is lower than that in the second
4.2 Paint Spray Processes
4.2.1 Paint Materials and Pretreatment
4.2.1.1 Paint Materials: The purposes of coatings are protection and aesthetics. The coat adhesion, durability, chemical resistance, and physical properties are among the protective purposes.
4.2.1.2 Pretreatment for Paint Process: Unlike the vehicle bodies in a body shop, the bodies in paint shops have all closures. Thus, before paint process, it is necessary to remove small devices used to keep the closures ajar during phosphate and E-coat p
4.2.2 Primer Application
4.2.3 Color Coat and Clear Coat Processes
4.2.4 Paint Equipment and Facilities
4.2.4.1 Spray Applicators: There are several types of paint applicators, such as airless gun, air spray applicator, and bell. A simple airless gun can spray a liquid paint by applying direct pressure on the paint. Industrial practice shows that airless sp
4.2.4.2 Paint Booth: The painting process has high environment requirements, should be performed in a closed environment with designed conditions. For example, the temperature and relative humidity in a paint booth should be controlled in designed ranges
4.3 Other Operations in Paint Shop
4.3.1 Paint Cure Process
4.3.1.1 Curing Process Parameters: In general, there are four main ovens for the processes of E-coating, sealing, primer application, and final coating. It is obvious that the curing process parameters, such as time and temperature, vary for different typ
4.3.1.2 Considerations on Curing: If the E-coat is not fully cured, sometimes called underbaked, the consequences can be severe. Possible issues contain poor corrosion of vehicle surfaces, poor adhesion to subsequent coating, wettability problems with sub
4.3.1.3 Wet Process: The paint coatings can be applied wet, instead of heating and drying each layer individually with energy-consuming ovens. Wet paint technology is a combination of process and coating materials that are the high solids, solvent-borne p
4.3.2 Nonpainting Operations
4.3.2.1 Sealing Operations in Paint Shop: After E-coat, the next processes is underbody (UB) coating and sealer applications. As a special process in a paint shop, there are two reasons for the coating and sealing applications. One is to cover areas or we
4.3.2.2 PUR Foam Applications: In addition, polyurethane (PUR) foam, a polymer, is injected into certain vehicle cavities to reduce the propagation of sound waves. For example, the cavity around the lower A-pillar, which is between the front wheel and dri
4.4 Exercises
4.4.1 Review Questions
4.4.2 Research Topics
4.5 References
Production Operations Management
5.1 Production Planning and Execution
5.1.1 Production Planning Approaches
5.1.1.1 Aggregate Planning: Aggregate planning is a medium-term planning method that outlines the quantity of materials and other resources, such as workforce, required for production. A generated plan covers a period of 6 to 18 months. Over a predefined
5.1.1.2 MPS: A master production schedule (MPS) is a fundamental planning effort and documentation that guides manufacturing operations. As a brief plan, MPS quantifies the processes, staffing, and inventory, as well as other key factors to optimize produ
5.1.1.3 MRP and MRP II: Material requirements planning (MRP) is a computer database system for production planning and inventory, focusing on the control of incoming materials and parts, and ordering and scheduling of subassembly inventories. The basic fu
5.1.1.4 ERP: A further expansion and development of MRP II is called enterprise resource planning (ERP). It is an enterprise-wide information database and communication system. It may be viewed as the third generation in an evolutionary path of manufactur
5.1.2 Push-Based and Pull-Based Execution
5.1.2.1 Distinction of Push and Pull: The difference between push-based and pull-based production control is in its planning and execution. During planning, it is assumed that the information for market demand, operation capacity, and major resources is a
5.1.2.2 Just In Time and Inventory: To effectively utilize all resources, all elements in a manufacturing system should be well balanced, which is often called production leveling. A well-leveled system produces neither too much nor too little and assures
5.1.2.3 Work in Process: There are always unfinished product units in manufacturing systems. These unfinished units are called work in process (WIP). WIP is in-process inventory, which costs money but adds no value to the customers. Therefore, it should b
5.1.2.4 Characteristics of Push and Pull: As the push and pull scenarios have their own advantages, it makes sense to consider applying the principles of both to take advantage of each. That is, some scenarios of push and pull may be cooperatively used. I
5.1.3 Production Control based on Customer Demands
5.1.3.1 Three Types of Planning and Execution: Production planning and execution can be further discussed based on vehicle ordering. For automotive manufacturing, there are three basic types of scenarios: 1) assemble (or make) to stock (ATS), 2) assemble
5.1.3.2 Characteristics of ATS and ATO: ATS plays a crucial role on vehicle availability to customers and keeping manufacturing cost low. The success of ATS relies on market research and forecasting. However, if the forecasting is too high, then the autom
5.2 Key Performance Indicators
5.2.1 Manufacturing Operational Performance
5.2.1.1 Basic Assessment of Performance: As discussed in early chapters, high volume, fixed line speed, and automation are among the main characteristics for vehicle assembly operations. All assembly lines should be running in predefined cycle time. In ot
5.2.1.2 Perspective on Operational Performance: Clearly, more dimensions of performance can be added to the web chart, depending on the emphasis and preference of operational management. As the performance drivers, KPIs should be carefully selected. Other
5.2.2 Production Throughput Measurement
5.2.2.1 Throughput Monitoring: Production throughput is the outcome of a manufacturing system. Throughput is one of the most important performance indications for manufacturing systems and is thus monitored in real time. Figure 5.11 shows a simple monitor
5.2.2.2 Other Influencing Factors: Another factor affecting production outcomes is quality. For complex products, such as automobiles, it is almost impossible to make every vehicle perfect. Various defects need to be repaired, reprocessed, or scrapped. Fi
5.2.3 Overall Equipment Effectiveness
5.3 Manufacturing Costs
5.3.1 Types of Manufacturing Costs
5.3.1.1 Operating Costs: The operating costs of automotive manufacturing include workforce, part inventory, equipment maintenance, utilities, etc. The main items in conventional cost accounting include labor, raw materials, overhead costs, etc. The materi
5.3.1.2 Overhead Costs: General and administrative (G&A) cost is a type of overhead cost, which incurs at the plant or even interplant level that are not associated with a specific plant or department. Examples are executives' salaries, salary employee ov
5.3.2 Economic Analysis of Equipment
5.3.2.1 Equipment Depreciation: Financially, any piece of equipment depreciates over time. Equipment depreciation is a noncash expense that has the effect of reducing taxes and therefore of changing cash flows for the operations, which affects the vehicle
5.3.2.2 Depreciation of Tooling and Facilities: For automotive manufacturing, all types of equipment are categorized into two groups, which is often for financial analysis purposes. One type is called tooling and the other facilities. The main difference
5.3.2.3 Economic Life of Equipment: With depreciation, any piece of equipment, machinery, or a manufacturing system has a different value over time. To evaluate equipment value, three factors need to be considered. The first is the initial cost, including
5.4 Equipment Maintenance Management
5.4.1 Equipment Maintenance Strategies
5.4.1.1 Types of Maintenance Management: There are various terms for the maintenance approaches. Maintenance management strategy and practice can be classified by maintenance behaviors. The three common types of maintenance are listed in Table 5.12 for co
5.4.1.2 Cost and Risk of Maintenance: Preventive maintenance still is a common practice in the industry. Maintenance scheduling can be viewed in basic two schemes: age based and block based. The difference is the time between consecutive maintenance activ
5.4.1.3 Total Productive Maintenance: In addition to the three types of maintenance practices above, a relatively new one is called total productive maintenance (TPM). Sometimes, TPM is considered part of lean manufacturing principles. Compared with the t
5.4.2 Maintenance Effectiveness
5.4.2.1 Measured by System Performance: The effectiveness of maintenance should be measured by system performance, such as OEE, throughput, total costs, and operation safety. One of the indicators for system performance is the equipment reliability. Here,
5.4.2.2 Measured by Total Cost: Total operation cost is another important indicator because of its strong association with maintenance effects. In general, good maintenance means very limited downtime. Often, the improvement of maintenance increases the c
5.5 Exercises
5.5.1 Review Questions
5.5.2 Research Topics
5.5.3 Analysis Problems
5.6 References
Quality Management for Vehicle Assembly
6.1 Introduction to Vehicle Quality
6.1.1 Recognition of Quality
6.1.2 Design for Quality
6.1.3 Manufacturing Quality Assurance
6.1.3.1 Overall Considerations for Manufacturing Quality: Quality management is a systematic approach for the assurance and continuous improvement of vehicle quality using all available resources. In manufacturing, quality management has two major efforts
6.1.3.2 Quality Inspections and Audits: For quality monitoring and improvement purposes, the necessary inspections and measures required in product quality assurance should be built into manufacturing processes. This way, quality issues can be detected ea
6.1.3.3 Total Quality Management: Total quality management (TQM) is a principle in doing business that attempts to maximize an organization's competitiveness through the continual improvement of the quality of its products and processes, as well as servic
6.2 Vehicle Manufacturing Quality
6.2.1 Assembly Joining Quality
6.2.1.1 Concept of Joint Quality: Structural quality is one of the quality focuses for vehicle assembly. With a good engineering design, the manufacturing execution ensures vehicle structural quality by targeting "every joint is a good one" of resistance
6.2.1.2 RSW Quality Assessment: In manufacturing, multiple measures are in place for the assurance of joint quality. They include direct destructive tests and indirect checks. Their main characteristics are listed in Table 6.5.
6.2.1.3 Other Joint Quality Inspections: Laser beam welding (LBW) has been increasingly used in automotive manufacturing. The LBW process is relatively new and complicated because of the variety of material grades, thickness, and shape to be welded, and l
6.2.2 Body Paint Quality
6.2.3 Vehicle Final Quality Audit
6.2.3.1 Final Inspections of Vehicles: After vehicles are completely built, comprehensive inspections of the entire vehicle quality are performed before the vehicles are shipped to dealership. For example, at the Toyota Georgetown (Kentucky) plant, 150 to
6.2.3.2 Assessment based on Final Audits: The standards, specifications, and containment procedures of vehicle quality inspections and audits vary with automakers. The audit criteria are based on engineering specifications and customers concerns, which ma
6.3 Dimensional Quality Management
6.3.1 Metrology Review
6.3.1.1 Fundamental Concepts: Dimensional measurement is a foundation for vehicle dimensional quality. The measurement data are composed of two components. One is the actual (true) value of the dimensions measured, and the other is the errors associated w
6.3.1.2 Repeatability and Reproducibility: On the topic of the precision or variation of data, there are two sources of variation: one is from the measurement device and the other from operators. Correspondingly, there are two key characteristics: repeata
6.3.2 Dimensional Quality Inspections
6.3.2.1 Quality Inspections in Manufacturing: The inspections of dimensional quality can be categorized into two scenarios: in production line and offline. Coordinate measurement machines (CMMs), like the one in Figure 6.16, are often used offline to meas
6.3.2.2 In-Line and Offline Inspections: From a quality assurance standpoint, the in-line inspections are preferred because of 100% product check in real time. The benefit is that its prompt feedback can make any delay of corrective actions and costly rep
6.3.3 Functional Build in Tryouts
6.4 Part Quality Management
6.4.1 Production Part Quality Assurance
6.4.1.1 Principle of PPAP: To ensure the quality of production parts provided by suppliers for a long term, a procedure PPAP is widely used. It addresses the production processes of the component/part suppliers (called organizations in PPAP) and demonstra
6.4.1.2 Requirements of PPAP: The entire PPAP process consists of a series of tests, analyses, reviews, and approvals. A PPAP package consists of up to 18 items, which are called elements. They are listed in Table 6.12 [6-18].
6.4.2 Quality Monitoring and Sampling
6.4.2.1 Principle of Sampling Plans: As mentioned above, materials and parts are substantial contributors to the quality of vehicles built. Therefore, the materials and parts should be monitored for quality assurance purposes. If found to not meet specifi
6.4.2.2 Discussion of Sampling Applications: As an example for discussion, a random sample (n = 60) for a shipment received is selected and defect (c = 1) is found. If the acceptable defect rate is p = 2%, what is the acceptance probability (P) of a shipm
6.5 Exercises
6.5.1 Review Questions
6.5.2 Research Topics
6.6 References
Operational Performance Improvement
7.1 Performance Improvement
7.1.1 Performance Continuous Improvement
7.1.1.1 Mindset of Continuous Improvement: Continuous improvement is a key element in lean manufacturing principles. Its activity and documentation are often referred to as "kaizen." In fact, the drive to improve continuously is not only for product quali
7.1.1.2 Employee Participation: The hallmark of continuous improvement is its empowerment of people and fostering their creativity. Everyone should be encouraged, empowered, and rewarded for participation in continuous improvement. Employee involvement no
7.1.2 Approaches of Continuous Improvement
7.1.2.1 Problem Solving Process: To work on root causes effectively, it is important to follow certain procedures and be data-driven. The common five-step problem solving and continuous improvement process is shown on the left of Figure 7.4. The five step
7.1.2.2 Structured Brainstorming Approaches: The manufacturing operations of vehicle assembly are so complicated that the root causes are not easily identified, even by experienced staff. In many cases, the early phase of problem solving and improvement p
7.1.2.2.1 Nominal group technique: This approach is a structured group method to encourage team brainstorming for problems and ideas. The goal is to increase team participation in problem identification and solution planning. This technique emphasizes eve
7.1.2.2.2 Affinity diagram: After team brainstorming exercises, many ideas surface. An affinity diagram helps take all the ideas and organize them into groups based on similarity and/or natural relationship. This method taps creativity and intuition. The
7.1.2.2.3 Force field analysis: Once the problem is identified, the analysis process starts identifying the factors. There are normally several factors influencing a problem. Some factors may be the restraints to the problem or goal and some factors may b
7.1.2.2.4 5-whys: This is an iterative interrogative tool utilized to explore the cause and effect relationships for a specific problem. The procedure is to define a problem first and then ask why the problem is. By repeatedly asking the sequential questi
7.1.3 Value Stream Analysis
7.2 Production Throughput Improvement
7.2.1 Production Throughput Analysis
7.2.1.1 Influencing Factors to Throughput: For a manufacturing system, the throughput can be measured by its outcome in a number or a rate. Vehicle assembly throughput can be viewed as the total amount of good vehicles produced in a given time. Subsequent
7.2.1.2 Case Study of Throughput Improvement: General Motors (GM) published its achievement on the throughput improvement, entitled "Increasing Production Throughput at General Motors," which won a 2005 Edelman Prize [7-7]. In the project, GM used the app
7.2.2 Production Downtime Analysis
7.2.2.1 Downtime Tracking: The main issue to the throughput is often downtime lost. The downtime of a system (line, workstation, or equipment) can be in various types and root causes. During operations, the downtime should be recorded on a timely manner.
7.2.2.2 Downtime Analysis: Finding and fixing the root cause of an issue is the key for the prevention of reoccurrence. There are many ways to do troubleshooting and root cause analysis. A summary document, such as a one page called "Downtime Problem Solv
7.2.2.3 Evaluation and Prioritization: Evaluating the issues can set the task priority for troubleshooting and prevention. An approach to assess future risks is based on the analysis of characteristics of the issue.
7.2.3 ProductionComplexityReduction
7.2.3.1 Reduction of Vehicle Configurations: There are many configurations for a vehicle model, even on mass produced ones. The common options of vehicles include various exterior colors, wheels, drivetrain, and seats, and interior choices. Possible optio
7.2.3.2 Batch Processing: In many cases, vehicle assembly production can be managed at the random mix of product configurations. However, planning and running production in a batch mode of configuration can be more effective. For example, a vehicle model
7.3 Bottleneck Analysis
7.3.1 Theory of Constraints
7.3.2 Stand Alone Availability
7.3.2.1 Distinction of SAA: In fact, the system availability (A) in OEE represents an overall status. Regarding availability, there are three possible reasons for nonworking situations. The first is the failures of the system itself. Next is that the syst
7.3.2.2 Stand Alone JPH: The concept of SAA can be applied to the actual production rate, called stand-alone JPH (or SAJPH). The SAJPH can be used to show the system performance in the same way as SAA, refer to (7.4).
7.3.3 Analysis of Buffer Status
7.4 Variation Reduction
7.4.1 Concept of Variation Reduction
7.4.2 Characteristics of Variation Reduction
7.4.3 Multivariable Correlation Analysis
7.4.4 Quality Concern on Parallel Lines
7.4.4.1 Data Distribution of Parallel Lines: Parallel configuration of manufacturing systems is more suitable and designed into some areas. Parallel setup creates a challenge to quality because the variables and their values in the parallel segments canno
7.4.4.2 Variation of Two Lines with Different Variances: However, the combined variance of two parallel lines is not very straightforward for understanding and analysis. Total variation (s2) of the products is affected by µ1, µ2, s1, and s2. A simple case
7.4.4.3 Variation of Two Lines with Different Means: A more realistic situation is that two subsystems have µ1 ? µ2 and s1 ? s2. Figure 7.35 shows the significant influence of ?µ (= µ2 - µ1) on the variation based on a simulation. In the analysis, the mea
7.4.4.4 Discussion of Parallel Line Variation: The above discussion can be observed in a manufacturing environment. In real-life cases, it is normal that both the data mean and variance are different between the parallel line segments. The resultant varia
7.5 Exercises
7.5.1 Review Questions
7.5.2 Research Topics
7.5.3 Analysis Problems
7.6 References
Index
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System requirements

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Automotive Vehicle Assembly Processes and Operations Management

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System requirements