机械专业英语.doc

Lesson 1 Job designJob designJob design involves specifying the content and methods of jobs. Job designers focus on what will be done in a job, who will do the job, how the job will be done, and where the job will be done. The objectives of job design include productivity, safety, and quality of work life.Ergonomics is an important part of job design. Ergonomics is the incorporation of human factors in the design of the workplace. It relates to design of equipment, design of work methods, and the overall design of the work environment. Among other things, ergonomics seeks to prevent common workplace injuries such as back injuries and repetitive-motion injuries by taking into account the fact that people vary in their physical dimensions and capabilities. Companies have compelling interests in reducing worker injuries since they result in lower productivity, lost workdays, and increases in health premiums.The factors that affect job design and the implications of various alternatives are often so complex that a person without a good background in job design is likely to overlook important aspects of it. Workers and managers alike should be consulted in order to take advantage of their knowledge and to keep them informed. Because they are intimately involved with the work, employees can be a source of valuable ideas for job improvements. Managerial support for job design depends on the commitment and involvement of managers. It is usually easier to sell a design to workers if they have been included in the process. Finally, establishing a written record of the job design can serve as a basis for referral if questions arise about it.Current practice in job design contains element of two basic schools of thought. One might be called the efficiency school because it emphasizes a systematic, logical approach to job design; the other is called the behavioral school because it emphasizes satisfaction of wants and needs. The efficiency approach, a refinement of Frederick Winslow Taylors scientific management concepts, received considerable emphasis in the past. The behavioral approach followed and has continued to make inroads into many aspects of job design. It is noteworthy that specialization is a primary issue of disagreement between the efficiency and behavioral approaches.SpecializationThe term specialization describes jobs that have a very narrow scope. Examples range from assembly lines to medical specialties. College professors often specialize in teaching certain courses, some auto mechanics specialize in transmission repair, and some bakers specialize in wedding cakes. The main rationale for specialization is the ability to concentrate ones efforts and thereby become proficient at that type of work.Sometimes the amount of knowledge or training required of a specialist and the complexity of the work suggest that individuals who choose such work are very happy with their jobs. This seems to be especially true in the “professions” (e.g., doctors, lawyers, professors) . At the other end of the scale are assembly-line workers, who are also specialists, although much less glamorous. The advantage of these highly specialized jobs is that they yield high productivity and relatively low unit costs, and they are largely responsible for the high standard of living that exists today in industrialized nations.Unfortunately, many of the lower-level jobs can be described as monotonous or downright boring, and are the source of much of the dissatisfaction among many industrial workers. While some workers undoubtedly prefer a job with limited requirements and responsibility for making decisions, others are not capable of handling jobs with greater scopes. Nonetheless, many workers are frustrated and this manifests itself in turnover and absenteeism. In the automotive industry, for example, absenteeism runs as high as 20 percent. Workers may also take out their frustrations through disruptive tactics such as deliberate slowdowns.The seriousness of these problems caused job designers and others to seek ways of alleviating them. Some of those approaches are discussed in the following sections. Before we turn to them, note that the advantages and disadvantages of specialization are summarized in Table 1.1. Major advantages and disadvantages of specialization in businessAdvantagesFor management:1.Simplifies training2.High productivity3.Low wage costsFor labor:1.Low education and skill requirements2.Minimum responsibilities3.Little mental effort neededDisadvantagesFor management:1.Difficult to motivate quality2.Worker dissatisfaction, possibly resulting in absenteeism, high turnover, disruptive tactics, poor attention to qualityFor labor:1.Monotonous work 2.Limited opportunities for advancement3.Little control over work 4.Little opportunity for self-fulfillmentBehavioral Approaches to Job DesignIn an effort to make jobs more interesting and meaningful, job designers frequently consider job enlargement, job rotation, job enrichment, and increased use of mechanization.Job enlargement means giving a worker a larger portion of the total task. This constitutes horizontal loadingthe additional work is on the same level of skill and responsibility as the original job. The goal is to make the job more interesting by increasing the variety of skills required and by providing the worker with a more recognizable contribution to the overall output. For example, a production workers job might be expanded so that he or she is responsible for a sequence of activities instead of only one activity.Job rotation means having workers periodically exchange jobs. A firm can use this approach to avoid having one or a few employees stuck in monotonous jobs. It works best when workers can be transferred to more interesting jobs; there is little advantage in having workers exchange one boring job for another. Job rotation allows workers to broaden their learning experience and enables them to fill in for others in the event of sickness or absenteeism.Job enrichment involves an increase in the level of responsibility for planning and coordination tasks. It is sometimes referred to as vertical loading. An example of this is to have stock clerks in supermarkets handle reordering of goods, thus increasing their responsibilities. The job enrichment approach focuses on the motivating potential of worker satisfaction.Job enlargement and job enrichment are also used in lean operations, where workers are cross-trained to be able t perform a wider variety to tasks, and given more authority to manage their jobs.The importance of these approaches to job design is that they have the potential to increase the motivational power of jobs by increasing worker satisfaction through improvement in the quality of work life. Many firms are currently involved in or seriously considering programs related to quality of work life.MotivationMotivation is a key factor in many aspects of work life. Not only can it influence quality and productivity, it also contributes to the work environment. People work for a variety of reasons in addition to compensation. Other reasons include socialization, self-actualization, status, the physiological aspects of work, and a sense of purpose and accomplishment. Awareness of these factors can help management to develop a motivational framework that encourages workers to respond in a positive manner to the goals of the organization. A detailed discussion of motivation is beyond the scope of this book, but its importance to work design should be obvious.Another factor that influences motivation, productivity, and employee-management relations is trust. In an ideal work environment, there is a high level of trust between workers and managers. When managers trust employees, there is a greater tendency to give employees added responsibilities. When employees trust management, they are more likely to respond positively. Conversely, when they do not trust management, they are more likely to respond in less desirable ways. The following reading discusses the issue of employees distrusting managers.TeamsThe efforts of business organizations to become more productive, competitive, and customeroriented have caused them to rethink how work is accomplished. Significant changes in the structure of some work environments have been te increasing use of teams and the way workers are paid, particularly in lean production systems.In the past, nonroutine job assignments, such as dealing with customer complaints or improving a process, were typically given to one individual or to several individuals who reported to the same manager. More recently, nonroutine assignments are being given to teams who develop and implement solutions to problems.There are a number of different forms of teams. One is a shortterm team formed to collaborate on a topic such as quality improvement, product or service design, or solving a problem. Team members may be drawn from the same functional area or from several functional areas, depending on the scope of the problem. Other teams are more long term. One form of longterm tram that is increasingly being used, especially in lean production setting, is the selfdirected team.Selfdirected teams sometimes referred to as selfmanaged teams, are designed to achieve a higher level of teamwork and employee involvement. Although such teams are not given absolute authority to make all decisions, they are typically empowered to make changes in the work processes under their control. The underlying concept is that the workers, who are close the most effective changes to improve the process. Moreover, because they have a vested interest and personal involvement in the changes, they tend to work harder to ensure that the desired results are achieved than they would if management had implemented the changes. For these teams to function properly, team members must be trained in quality, process improvement, and teamwork. Selfdirected teams have a number of benefits. One is that fewer managers are necessary; very often one manager can handle several teams. Also, selfdirected teams can provide improved responsiveness to problems, they have a personal stake in making the process work, and they require less time to implement improvements.Generally, the benefits of teams include higher quality, higher productivity, and greater worker satisfaction. Moreover, higher levels of employee satisfaction can lead to less turnover and absenteeism, resulting in lower costs to train new workers and less need to fill in for absent employees. This does not mean that organizations will have no difficulties in applying the team concept. Managers, particularly middle managers, often feel threatened as teams assume more of the traditional functions of managers.Moreover, among the leading problems of teams are conflicts between team members, which can have a detrimental impact on the effectiveness of a team.Expert Robert Bacal has a list of requirements for successful team building:1. Clearly stated and commonly held vision and goals.2. Talent and skills required to meet goals.3. Clear understanding of team members roles and functions.4. Efficient and shared understanding of procedures and norms.5. Effective and skilled interpersonal relations.6. A system of reinforcement and celebration.7. Clear understanding of the teams relationship to the greater organization.Lesson 2 Methods AnalysisOne of the techniques used by self-directed teams and work analysts is methods analysis, which focuses on how a job is done. Job design often begins with an analysis of the overall operation. It then moves from general to specific details of the job, concentrating on arrangement of the workplace and movements of materials and/or workers. Methods analysis can be a good source of productivity improvements.The need for methods analysis can come from a number of different sources:1. Changes in tools and equipment.2. Changes in product design or introduction of new products.3. Changes in materials or procedures.4. Government regulation or contractual agreement.5. Other factors (e.g., accidents, quality problems)Methods analysis is done for both existing jobs and new jobs. For a new job it is needed to establish a method. For an existing job the procedure usually is to have the analyst observe the job as it is currently being performed and then devise improvements. For a new job, the analyst must rely on a job description and an ability to visualize the operation.The basic procedure in methods analysis is as follows:1. Identify the operation to be studied, and gather all pertinent facts about tools, equipment, materials, and so on.2. For existing jobs, discuss the job with the operator and supervisor to get their input.3. Study and document the present method of an existing job using process charts. For new jobs, develop charts based on information about the activities involved.4. Analyze the job.5. Propose new methods.6. Install the new methods.7. Follow up implementation to assure that improvements have been achieved.Selecting an Operation to Study. Sometimes a foreman or supervisor will request that a certain operation be studied. At other times, methods analysis will be part of an overall program to increase productivity and reduce costs. Some general guidelines for selecting a job to study are to consider jobs that1.Have a high labor content.2.Are done frequently.3.Are unsafe, tiring unpleasant, and /or noisy.4.Are designated as problems (e.g., quality problems, processing bottlenecks).Documenting the Current Method. Use charts, graphs, and verbal descriptions of the way the job is now being performed. This will provide a good understanding of the job and serve as a basis of comparison against which revisions can be judged.Analyzing the Job Proposing New Methods. Job analysis requires careful thought about the what, why, when, where, and who of the job. Often, simply going through these questions will clarify the review process by encouraging the analyst to take a devils advocate attitude toward present and proposed methods.Analyzing and improving methods is facilitated by the use of various charts such as flow process charts and worker-machine charts.Flow process charts are used to review and critically examine the overall sequence of an operation by focusing on the movements of the operator or the flow of materials. These charts are helpful in identifying nonproductive parts of the process (e.g., delays, temporary storages, distances traveled).Figure 7.1describes the symbols used in constructing a flow process chart , and Figure 7.2 illustrates a flow process chart.The use for flow process charts include studying the flow of material through a department, studying the sequence that documents or forms take, analyzing movement and care of surgical patients, layout of department and grocery stores, and mail handling.Experienced analysts usually develop a checklist of questions they ask themselves to generate ideas for improvements. The following are some representative questions:1.Why is there a delay or storage at this point?2.How can travel distances be shortened or avoided?3.Can materials handling be reduced?4.Would a rearrangement of the workplace result in greater efficiency?5.Can similar activities be grouped? 6.Would the use of additional or improved equipment be helpful?7.Does the worker have any ideas for improvements? A worker-machine chart is helpful in visualizing the portions of a work cycle during which an operator and equipment are busy or idle. The analyst can easily see when the operator and machine are working independently and when their work overlaps or is interdependent. One use of this type of chart is to determine how many machines or how much equipment the operator can manage. Figure 7.3 presents an example of a worker-machine chart, where the “worker” is actually a customer weighing a purchase in the bulk-foods section of a supermarket. Among other things, the chart highlights worker and machine utilization.Installing the Improved Method. Successful implementation of proposed method changes requires convincing management of the desirability of the new method and obtaining the cooperation of workers. If workers have been consulted throughout the process and have made suggestions that are incorporated in the proposed changes, this part of the task will be considerably easier than If the analyst has assumed sole responsibility for the development of the proposal.If the proposed method constitutes a major change form the way the jib has been performed in the past, workers may have to undergo a certain amount of retraining, and full implementation may take some time to achieve.The Follow-Up. In order to ensure that changes have been made and that the proposed method is functioning as expected, the analyst should review the operation after a reasonable period and consult again with the operator.Process chart symbolsOperationA large circle indicates an operation such asDrive nailMixComputer/word processingTransportationAn arrow indicates a transportation, such asMove material by cartMove material by conveyorMove material by carrying(messenger)A triangle indicates a storage, such asRaw material in bulk storageFinished stock stacked on palletsProtective filling of documentsDelayA large Capital D indicates a delay, such asWait for elevatorMaterial in truck or on floor at bench waiting to be processedPapers waiting to be filedInspectionA square indicates an inspection, such asExamine material for quality or quantityRead steam gauge on boilerExamine printed form for informationLess