We were interested in observing a small business rather than a large corporation. Such a setting represents the kind of workplace in which employees will find themselves in the 21st century, due in part to the downsizing of large corporations and the growth of smaller firms. We looked, in particular, for a sector of industry that requires the use of advanced technology, which is increasingly becoming more common in the workplace. In addition, because more than 75% of today's workers have completed between 12 and 15 years of schooling (U.S. Department of Labor, 1994, pp. 160-161), we wanted to focus on a firm in which the majority of employees have a prebaccalaureate background.
A site that met all these requirements was a circuit-board manufacturing plant, which we will call Company X, located in the Silicon Valley of California. Company X assembles circuit boards to order. Its customers are electronics companies from aerospace, computer, or medical industries, who outsource their manufacturing in order that they themselves may focus on engineering and product development. Outsourcing is a growing industry today. One important characteristic of this company is that it is in a highly competitive market. To survive, the company must have leading-edge equipment, be able to do a fast turnaround on a job, and provide excellent quality control. Employees have a large stake in the success of this firm. The quality of the product determines whether or not the company will win more contracts or simply fold.
The first author spent three months on the manufacturing floor observing and videotaping the workers. Although they were asked questions during actual tasks in order to clarify what was happening, every effort was made not to interfere with the pace of the work. These observations were supplemented with more formal and extended interviews with six of the workers, two supervisors, the manufacturing manager, and the company president. The interviews, which were audiotaped, provided information on the company's history and structure, the participants' background and education, the kinds of tasks performed, and the functions of the different machines. A total of 15 hours of videotaped task activities and 20 hours of audiotaped interviews were transcribed. (For a list of Transcription Conventions and the Full Transcription, see Appendix A. Communication in Vietnamese was also transcribed and translated.)
Company X is composed of approximately 120 employees, 80 of whom work on the manufacturing floor. Jobs range from unskilled and semiskilled, such as preparing parts or hand-placing them on the board, to skilled labor, such as operating computerized machines, soldering, or testing the completed circuit boards. Workers can have a career path within this company. Some of the workers in Company X have been promoted from unskilled to skilled jobs and even to supervisory positions. Almost all jobs have multi-task functions, and some tasks require programming skills. The work is carried out by teams of workers at stations.
A feature of this company is the ethnolinguistic diversity of its employees--people of Chinese, Latino, Middle Eastern, and Vietnamese background, along with African Americans and European Americans. Some workers are recent immigrants with green cards, most of whom come from Mexico and Vietnam. The teams generally organize themselves by ethnolinguistic background, an arrangement that is supported by the management because it perceives that these groups work well together. These arrangements do not have tight boundaries, however, as other members on a given team may include native speakers of other languages. Moreover, individuals move across teams when they are needed for troubleshooting, making last minute changes requested by the customer, or meeting deadlines. As they work, the groups play their music of choice, forming a cacophony of ethnic sounds, which mingle with the blare of the machines.
Within this setting, workers frequently take part in troubleshooting activities. We isolated one incident for analysis because of its typicality: a team of workers engaged in complex problem-solving at a high-tech machine. The focal participants in the interaction analyzed here are two Vietnamese workers: Tran[2], a 32-year-old machine operator, and Du, his supervisor. These two men form part of a team of six who work in one of the circuit-board assembly departments. Five workers are from Vietnam, and one is from the United States. Tran came to this country as a refugee at the age of 14; he completed high school here and eventually earned an associate's degree in computer science from a community college. Du, who is now reaching the age of retirement, also arrived as a refugee from Vietnam, where he had completed secondary school. In this country, Du studied briefly at a technical institute in order to become an electrician. An opportunity came for him to take a job in manufacturing, however--work that he has continued doing for more than 15 years. Both men are experienced in their respective jobs, and both have received occasional on-the-job training at Company X. Just prior to this study, they were trained to operate new high-tech machines recently acquired for their department. Before examining Tran and Du's interactions, it is necessary to describe the circuit boards they assemble and the equipment that they use to accomplish the task.
Today, circuit boards are ubiquitous. Not only are they used in PCs, but they can also be found in other machines used for homemaking, work, transportation, and leisure. Circuit boards come in different sizes and contain a variety of interconnected components, which themselves vary in size. Specific examples of components include integrated circuits, resistors, capacitors, magnetics, crystals, and sockets. Some components are secured to the board with through-hole punching. Others are attached to the surface of a board that has been covered with a thin layer of solder paste. One component, the socket, bears some description because it figures importantly in the interaction described below. Sockets are relatively large receptacles for components that have a big turnover. Because these other components are plugged into sockets rather than soldered to the board directly, they can be replaced easily by newer versions. Thus, using sockets can be economically advantageous for end users, as well as designers, since the latter can upgrade existing boards rather than having to manufacture new ones.
In general, components that are assembled on circuit boards have become much smaller over time. Because circuit-board technology is undergoing this rapid miniaturization, manufacturing technology must keep pace. This means that the machines designed to assemble the boards can have a life cycle of only six months to a year. Company X uses both older-generation machines--for through-hole assembly--and newer ones, which have surface mount technology (SMT). Often, a customer requires boards that contain a combination of through-hole and SMT assembly.
Both types of machine must be programmed to place components on boards at assigned points on an x/y axis. The machine programmer uses a customer's bill of materials, a blueprint, and sometimes a sample board as a basis for data entry. In a small office just off the floor, the programmer enters the information into a database, then converts the program to SMT-based software and takes the disk to the machine operator. The machine in Figure 1 is equipped with a robotic arm and a vision system designed for accurate placement of components. The operator can input and modify data using the operator panel and Cathode Ray Tube (CRT) display on the machine. The components are fed from feeders arranged in slots along the front and back of the machine. Reels of tape containing these components are placed on the feeders.[3] Each time the robotic arm "picks" a component from the reel, the feeder moves another component into place for the next pick. The first board in a series, having been prepared with a film of solder paste, moves on a conveyor belt through each machine, where the arm picks components from feeders and places them at designated points. During the trial run, the operator has the option of moving the arm in slow motion. Once the first board is assembled accurately, the other boards are run at high speed. A single job for a customer can range from assembling just a few boards to several thousand boards, using from one to three SMT machines.
[2] The participants' names are pseudonymous.
[3] Other feeders may hold sticks or trays of components. For the purposes of this paper, we will focus on the reels as illustrated in Figure 2. All diagrams of the SMT machine and its parts are from the manufacturer's instruction manual and are reproduced with permission from Zevatech, Inc.
