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Productivity. One of the most important responsibilities of an operations manager is to achieve productive use of organization’s resources.
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Productivity • One of the most important responsibilities of an operations manager is to achieve productive use of organization’s resources. • Productivity is an index that measures output (goods and services) relative to the input (capital, labor, materials, energy, and other resources) used to produce them. • It is usually expressed as the ratio of output to input: Output Productivity = --------------- Input
Ways to Increase Productivity • Increase output by using the same or a lesser amount of (input) resource. • Reduce amount of (input) resource used while keeping output constant or increasing it. • Use more resource as long as output increases at a greater rate. • Decrease output as long as resource use decreases at a greater rate. • Productionis concerned with the activity of producing goods and services. • Productivity is concerned with the efficiency and effectiveness with which these goods and services are produced.
Efficiency and Effectiveness for productivity improvement. • Efficiency is a necessary but not a satisfactory condition for productivity. In fact, both effectiveness and efficiency are necessary in order to be productive. • Efficiency is the ratio of actual output generated to the expected (or standard) output prescribed. • Effectiveness, on the other hand, is the degree to which the relevant goals or objectives are achieved. • Effectiveness involves first determining the relevant (right) goals or objectives and then achieving them. • If, for example, nine out of ten relevant goals are achieved, the effectiveness is 90%. One can be very efficient and still not be productive.
Production improvement does not necessarily mean productivity improvement. • Suppose a bank processed 1,000 checks yesterday, using 20 hours of labor. • Let’s say that the same bank processed 1,200 checks today, using 24 hours. • Production has increased by 20%, from 1,000 to 1,200 checks. However, the labor productivity for this operation is unchanged, because 1,000 / 20 is equal to 50 checks per hour yesterday, and 1,200 / 24 is equal to 50 checks per labor hour today. • Therefore, improvement in production does not necessarily generate improvement in labor productivity.
Efficiency improvement does not guarantee productivity improvement. (continue…….) • For example, suppose a doctor amputates (cuts) a patient’s leg in half the usual time and boasts (show off) the nurses,” • I have been twice as efficient as in the past.” • The nurses, who view the situation say something differently, “ • What a disaster – the doctor amputated the wrong leg!” • Here, the doctor’s effectiveness was zero because he did not achieve the relevant goal, even though his efficiency improved by 200%.
Single Factor Approach to Measuring Productivity • Capital - Number of products produced divided by asset value • Materials - Number of products produced divided by dollars spent on materials • Direct Labor - Number of products produced divided by direct labor-hours • Overhead - Number of products produced divided by dollars spent on operating cost
Variables Affecting Labor Productivity • Physical work environment • Technology, equipment, materials, lighting, layout • Product quality • Defects, scrap, rework • Employee job performance • Employee ability, motivation
Employee Job Performance • Behavioral scientists believe that individuals are motivated to act in a certain way by a desire to satisfy certain needs. Maslow ‘s hierarchy of needs Fulfillment Recognition Affiliation Security Physiological
Maslow ‘s hierarchy of needs • At the bottom of the hierarchy are physiological needs. These are the basic needs that must be met to sustain life itself. Satisfying ones physiological needs will be the primary concern of any person and until one has done so one will not be concerned with any other issues. • However, once workers feel reasonably sure of fulfilling their physiological needs, they will seek to satisfy the next need in the hierarchy, that of security. • Security is taken to mean a feeling of protection againstphysical and psychological harm, as well as security of employment. • For workers who have already satisfied their physiological and their security needs, the next motivating factor is that of affiliation, that is wanting to belong to a group or an organization and to associate with others. • Next on the hierarchical scale is the need to be recognized, and this is followed by the need for fulfillment (also called “self-actualization”). • This last need expresses the desire of people or workers to be given an opportunity to show their particular talents.
Modifying Jobs to ProvideBroader Range of Needs Satisfaction • Cross – training – workers perform multiple jobs • Job enlargement is a “horizontal” expansion of job tasks; that is, the worker is assigned more tasks at the same general skill level. • In a manufacturing setting, job enlargement might mean having a worker do several tasks at a work station rather than only one or two. • In a bank, it might mean training a person to write car loans, and installment loans rather than only one of these. • Job Enrichment involves “vertical” expansion of a job’s responsibilities and skills. • It may mean that a production worker is involved in the design of the product or production process is responsible for his own quality testing, handles customer complaints, or deals directly with suppliers. • Team production -- organizing workers into teams; assigning management responsibility to teams
METHODS ANALYSIS AND IMPROVEMENT • Specifying the tasks and responsibilities of a job is only the first step in the job design process. • The next step is to determine how to perform the tasks, that is, determine the best work methods. • Best work methods are • the most efficient physical movements of the worker, • the best sequence in which to perform movements or tasks, and • the best way to coordinate the workers actions with those of machines and other workers. • This information must be conveyed to the workers through training and appropriate supervision and feedback.
METHODS ANALYSIS • A logical approach to deciding what tasks should be done and how they should be done is called methods analysis. • Methods analysis utilizes • structured data collection, • visual aids and charts, and • logical procedures to help understand and improve work methods. • Methods analysis relies on obtaining good observational and experimental data. • Methods analysis focuses primarily on the activities of individual workers or groups of related workers.
Work Measurement • Work measurementis the process of establishing the time that a given task would take when performed by a qualified worker working at a defined level of performance. • A qualified worker is one who has acquired theskill, knowledge and other attributes to carry out the work in hand to satisfactory standards of quantity, quality and safety • Work measurement also refers to the process of estimating the amount of worker time required to produce one unit of output. • A goal of work measurement is to develop labor standards that can be used for planning and controlling operations.
Labor Standards • A labor standard is the number of worker-minutes required to complete an element, operation, or product under ordinary operating conditions. • Labor standards are used in: • Cost estimation • Pricing of products and services • Incentive pay systems • Capacity planning • Production scheduling • A labor standard can be determined using one or more of the following approaches: • Time study • Work sampling • Predetermined time standards
Time Study • Job is performed by a single worker in a fixed location • Job involves repetitive short cycles • Job is expected to continue unchanged for a long period • Job produces large quantities of output • Resulting time standard must be very accurate • Analysts use stopwatches to time the operation being performed by workers • These observed times are then converted into labor standards • The labor standards are expressed in minutes per unit of output for the operation
Determining Labor Standardsfrom Time Studies Performance Rating Allowance Fraction Observed Time Normal Time Standard Time
Example: Time Study Approach In a time study of a manufacturing operation, the average time observed to complete a product was 8.6 minutes. The performance rating applied to the observed worker was 0.95 and the allowance during an 8-hour shift was 12.5% or 60 minutes. Compute the labor standard.
Example: Time Study Approach Observed time = 8.6 minutes Performance rating = 0.95 Allowance fraction = 0.125 Normal time = Observed time x Performance rating = 8.6 x 0.95 = 8.17 minutes Standard Time = Normal time / (1 - Allowance) = 8.17 / (1 - 0.125) = 8.17 / (0.875) = 9.337 minutes
Work Sampling • The work of one or more employees is randomly sampled at periodic intervals • The results of these studies are used to: • Set allowances used in labor standards • Set labor standards
Work Sampling • Job performed by a single worker in a fixed location • Job involves repetitive short cycles • Job expected to be changed periodically as customer orders change • Job produces relatively small quantities of output • Resulting time standard used for accounting cost standard, pricing analysis, and production planning
Example: Work Sampling A work sampling study was performed on an electronic assembly operation at OK Instruments. The study covered an 8-hour shift with a single worker. The results of the study were: Activity% of Worker’s Time Assemble Units 80 Allowances 20 If the worker received a performance rating of 1.20 on the Assemble Units activity and 400 units were assembled during the study, what is the labor standard for this operation?
Example: Work Sampling 1) Compute the average time per assemble: Total Minutes of Assembly Work Number of Units Assembled = 0.80(480)/400 = 0.960 minutes per unit 2) Compute the normal time per unit: = (Average Time per Unit) (Performance Rating) = 0.960 (1.20) = 1.152 minutes per unit 3) Compute the labor standard: = Normal Time / (1 – Allowance Fraction) = 1.152 / (1 - 0.20) = 1.44 minutes per unit
