Showing posts with label Industrial Engineering. Show all posts
Showing posts with label Industrial Engineering. Show all posts

Industrial Engineering & Production Management

Basics of Industrial Engineering and Production managements with complete course outline and syllabus as taught to students in mechanical engineering. It is important to know that only engineers can perform better at management jobs related to production and industrial manufacturing. So it is very important for mechanical engineers to revise basic concepts of production management.

Production Management - Introduction

The production management deals with the design of the production system (which includes product, process, plant, equipment etc.) and development of the control system to manage inventories, product quality, production schedules and productivity.

Industrial Engineering - Introduction

The industrial engineering is an engineering approach to the detailed analysis of the use and cost of the resources of an organization. The main resources are men, money, materials, equipment and machinery. An industrial engineer carries out such analysis in order to achieve the objectives (to increase productivity or profits etc.) and policies of the organization.

Work Study

The work study consists of two techniques namely method study and work measurement. The pioneer work in this field was done by F. W. Taylor and Frank B. Gilbreth.

The.method study is a technique to simplify the job and develop more economical methods of doing it.

The work measurement is concerned with the elimination of ineffective time (the time during which no productive work is being performed) and establishment of time standards for a job.

The objectives of method study are as follows:

1. To improve the total performance of the operating unit.
2. To maintain performance at the highest level during any given time and continuously to improve on that level.

The method study can be applied to almost all types of work, whether it be a factory, clerical or any other type of activity. The following is the basic procedure in the application of method study:

(a) Select the job or process to be studied.
(b) Record all facts about the present method by direct observation.
(c) Examine these facts critically.
(d) Develop the most practical, economic and effective method.
(e) Install the new developed method as a standard practice.
(f) Maintain the standard practice by regular routine checks.

The success of method study depends on the accuracy with which the facts are recorded.

Symbols Used in Work Study

The work study is done by means of a stop watch. In work study, all the activities are broken down into five basic types of events and each is represented by a symbol, as follows:

(a) Operation:  It involves a change in the location or condition of a product.
(b) Inspection:  It is an act of checking for correctness of the quantity or quality of the items.
(c) Transport:  It indicates the movement of an item from one location to another.
(d) Delay:  It occurs when something stops the process and a product waits for the next event.
(e) Storage:  It represents a stage when a finished good or raw material awaits an action or when an item has been retained for quite some time for reference purposes.

String Diagram

The string diagram is used in production management systems for:

(a) for checking the relative values of various layouts,
(b) where group of workers are working at a place, and
(c) where processes require the operator to be moved from one work place to other.

Work Measurement in Production Management

The work measurement is the application of techniques to establish the time for a qualified worker to carry out a specified work at a defined level of performance. The objectives of work measurement are as follows:

(a) To plan and schedule of production,
(b) To formulate a proper incentive scheme, and
(c) To estimate the selling prices and delivery dates.

The principal techniques used to measure work are

(a) Time study,
(b) Predetermined motion time system (PMTS),
(c) Analytical estimating, and
(d) Activity (work) sampling.

Time Study in production planning

The general procedure followed in systematic carrying out the time study in production planning is as follows:

1. Select the work to be studied.
2. Record all the information about the work, operator and surrounding conditions.
3. Break down the each operation into small elements.
4. Examine each element to ensure that the most effective method and motions are used.
5. Measure with a stop watch, the time taken by the operator to perform each element.
6. Assess the effective speed of the operator performance, i.e. rating factor.
7. Apply rating factor to the observed time to get basic or normal time.
8. Determine the allowances to be made.
9. Compile standard time.

(a) The standard time or allowed time is the total time in which a job should be completed at standard performance. It is obtained by adding all allowances to the basic time or normal time.
(b) The average of times recorded by a work study man for an operation is called representative time.
(c) The actual time read from a stop watch during time study is known as observed time.
(d) The assessment of performance of the operator by the time study man is known as rating factor.

Pre-determined Motion Time System (PMTS)

Pre-determined Motion Time System (PMTS) - It is the work measurement technique to build up time for manual work making use of pre-determined elemental motion times. The following are the few methods of PMTS.

(a) Method Time Measurement (MTM)
(b) Work Factor System (WFS)
(c) Basic Motion Time Study (BMTS)
(d) Motion Time Analysis (MTA)

Micromotion Study for Production Management

The micromotion study was originated by Frank B. Gilbreth. The study is based on the idea of dividing human activity into division of movements, known as Therbligs. It is the name given to the micromotion of an operation.

The study consists of analyzing a motion picture taken during the performance of work. The time taken for each fundamental motion is accurately indicated in the film by a timing device. The purpose of micromotion study is to assist in finding out the most efficient way of doing work. It also train the individual operator regarding the motion economy principles and help in collecting the motion time data for synthetic time standards.

Break-even Analysis

The break-even analysis in production management and industrial engineering consists of total cost (i.e. fixed cost and variable cost) and sales revenue. The fixed costs do not increase or decrease with the sales or production such as rent, insurance, salaries etc. The variable costs increase or decrease with the sales or production such as raw material, direct labor, indirect material etc. The point at which a business neither makes a profit nor incurs a loss, is known as break even point. It is a point when sales revenue and total cost lines intersect.

Wage Incentive Plans in Production Management

Various wage incentive plans and strategies are used by project managers for production plants. Details of some wage incentive plans are given below:

1. Straight piece work system. In this system, the worker is paid at a specified piece rate, for the number of pieces or units produced by him. The standard output is set and the worker is guaranteed a minimum wage. Thus, if a worker produces less than the standard output, he will get the minimum guaranteed wage. If another worker produces more than standard output, he is paid a wage in direct proportion to the number of pieces produced by him at the specified piece rate.

2. Halsey plan. In this system, a standard time is set from past production records for the completion of a job. The worker is guaranteed a minimum wage. If a worker completes the job in the standard or more than the standard time, he is paid at his guaranteed time rate. If a worker completes the job in less than standard time, he is paid a bonus in addition to his base wage at the guaranteed time rate. The amount of bonus varies from 30 to 50 percent of the time saved. If R is the base rate guaranteed per hour, S is the standard time for the job and T is the actual time, then according to Halsey 50-50 plan, the wages for the job will be

3. Rowan plan. In this system, an hourly rate is guaranteed, standard time for the completion of job is established from the past production record. If the job is completed in the standard or more than the standard time, the worker is paid the guaranteed wage. If the job is completed in less than the standard time, the worker is paid a bonus in addition to the guaranteed wage.

According to Rowan plan system, the total earning of the work or wages for the job is given by

4. Gantt plan. In this system, output standard for a given time (standard task level) is set by a careful scientific study of the work. If a worker reaches the standard task level, he is paid a bonus which is usually one-third of task rate. If the worker fails to reach the set standard, he is paid only the guaranteed wage.

5. Emerson's efficiency plan. In this system, a standard time is established for each job. During each pay period, the number of hours taken by each worker to complete the job is recorded. The efficiency of each worker is calculated which is given as the ratio of the standard time for the job to the time taken by the worker.

The worker is guaranteed his time rate. The work standard is set at a high level. If the efficiency is 66% or below, then the worker is paid his guaranteed wage and no bonus is paid. At 67% efficiency, the worker is paid this time rate plus a small bonus. The bonus increases with the increase in efficiency.