28 Industrial Engineering

C. S. Sentthil Kumar

epgp books

 

 

 

 

Introduction

 

In the current scenario of competitive market environment, there is tremendous pressure on the manufacturing industries to keep their cost of production as low as possible without compromising on the quality, quick response to market – that is – shorter lead times, optimum utilization of manufacturing resources. To achieve all these, a scientific and systematic approach to the manufacturing is required. Industrial engineering is one such method which ensures a thorough and systematic analysis of manufacturing process and all the input resources that go into this process. Nowadays the manufacturing setup requires a system based approach rather than human resource based approach. In short this means irrespective of whoever is doing a job or process and whenever it is done it should give the same output with optimum utilization of resources consistently.

 

LEARNING OBJECTIVES

  • At the end of this lesson you will be able to Understand the fundamentals of industrial engineering
  • Know about various tools and concepts in industrial engineering
  • Understand the application of industrial engineering towards achieving higher enterprise efficiency.

  What is Industrial Engineering

 

Before making a foray into the world of industrial engineering it is important to understand certain basic terminologies used in a manufacturing industry.

 

Production: The processes and methods used to transform tangible inputs (raw materials, semi-finished goods, subassemblies) and intangible inputs (ideas, information, knowledge) into goods. Resources are used in this process to create an output that is suitable for use or has an exchange value.

 

Efficiency: The comparison of what is actually produced or performed with what can be achieved with the same consumption of resources (money, time, labor, etc.) with set conditions.

 

In simple terms it is the ratio between actual output and the capacity. It is an important factor in determination of productivity.

 

Productivity: Productivity is commonly defined as a ratio between the output volume and the volume of inputs. It measures how efficiently inputs – labour, material and capital, are being used to produce a given level of output. It provides an insight into how to capitalize on these same input resources to achieve a higher output or achieve the same output with reduction in consumption of these resources. Productivity is considered a key source of industry’s growth and competitiveness in the current highly competitive market environment. (courtesy: www.businessdictionary.com)

 

Industrial engineering comes as powerful concept to optimize these terminologies. It is defined by the Institute of Industrial Engineers as: “Industrial engineering is concerned with the design, improvement and installation of integrated systems of people, materials, information, equipment and energy. It draws upon specialized knowledge and skill in the mathematical, physical, and social sciences together with the principles and methods of engineering analysis and design, to specify, predict, and evaluate the results to be obtained from such systems”.

 

What Industrial Engineering does?

 

Industrial engineering determines the most effective way the basic resources in a manufacturing set up can be used to make a product.

 

The concept of industrial engineering consists of many sub concepts. To cite a few:

 

Operation research: The concept which uses analytical methods to analyze and design the components of a manufacturing system and help the management to make better decisions on optimum utilization of these components.

 

Operation management: A management concept concerned with installing and controlling the process of production and redesigning operations in the production of goods to improve their effective utilization.

 

Job design: Operation is broken down into jobs and designed to the required specification, methods and relationship between jobs to meet technical and organizational requirements. Job design also takes into account ergonomics, work station design and work environment design.

 

Supply chain management: This manages storage and flow of raw materials, work-in-process inventory, and finished goods from point of origin to point of consumption. This also includes flow of data in the reverse direction which is essential ensure smooth SCM

 

Cost engineering: Most of the managements tend to view individual departments in the manufacturing unit as cost centers. This facilitates cost planning and management at micro level rather than macro level which has been in practice.

  • Concepts in industrial engineering
  • Enterprise Resource Planning (ERP)
  • Customer Relationship Management (CRM) Supply Chain Management (SCM)
  • Business Intelligence (BI) Systems Dynamic (SD)

The demand for industrial engineering continues to grow due to urging need of the enterprise to optimize their functioning through reduction of costs, increased productivity, quick response to fast changing market, increased competition etc.

 

Nature of work of industrial engineer

 

Role of an industrial engineer is multifaceted and he/she is often is required to perform in whole or in certain areas. This will largely depend on the industry and role the management has envisaged for the industrial engineer. Role of the industrial engineer includes the following but not restricted to these alone.

  1. Process Improvement Expert
  2. System Integrator
  3. Change Agent
  4. Demand Forecaster and Capacity Planner and Manager
  5. Productivity Expert

 

The industrial engineer normally performs the following jobs.

  • Analyzing the product to be manufactures and its usage and manufacturing requirements Developing management control systems for financial planning and cost analysis
  • Designing production planning and control systems to coordinate activities and control product and process quality
  • Developing job evaluation and operator evaluation systems
  • Responsibilities of Industrial Engineer:
  • By applying the work measurement and motion study techniques Industrial engineer does the following work:
  • Planning plant, department and machinery layouts using various tools like travel chart, string diagram, PERT and CPM
  • Monitoring and controlling Production flow system using various types of flow charts Allocating the machines and operator for a specific job or operation
  • Monitoring and improving the operator performance Production and quality control system

To be successful an industrial engineer needs to possess skill sets, namely

  1. Technical expertise – to understand the process, process requirements and process improvement
  2. Managerial expertise – to effectively take along all the stake holders for ultimate improvement in enterprise efficiency
  3. Leadership – which is essential to take initiative and implement changes

Benefits of Industrial Engineering

  • Provides a scientific and systematic method to streamline and improve productivity and efficiency.
  • Helps to establish more efficient and profitable business practices while increasing customer service and quality.
  • Makes work place and environment safer, faster, easier, and more rewarding.
  • Management can analyze processes and improve them through optimization and waste reduction. Reduces cycle time and increases throughput and thereby improves competitiveness, profitability, and reduces resource requirements.

Application of Industrial Engineering

 

Components of Industrial Engineering

  1. Work Design, Work Station Design, Ergonomic Analysis
  2. Automation, Process Control and Quality Control
  3. Production System design and control

    One of the popular tools used in industrial engineering is Work Study. Work Study has two strategies or components – Work Measurement and Method Study.

 

The work measurement mainly focuses on analyzing, calculating the time required to perform a job or work or an operation. This eventually facilitates categorizing the total time consumed as 1. Effective time and 2. Ineffective time

 

Method Study mainly focuses on investigating the way in a job or work or an operation is done in terms of how, whom and when. Method study leads to alternatives ways to do the same job and finally arriving at best way to do the job. Method study is done at both macro and micro levels. Method study is also known as Methods Engineering and its main purpose is operation analysis and design

 

Application of Method or Motion Study and Work Measurement in industrial engineering Method Study Definition: Method study is defined as systematic investigation and recording of the existing method of doing a job in order to develop an alternative method or modify the existing method so that the new method will be easier, simple, quick, efficient and less fatiguing at possibly lesser cost. This may be achieved by eliminating unnecessary motions or by changing  the sequence of operation or the by changing the process of manufacture itself. The aim of method study is to make the job simpler and less fatiguing for the labour.

 

Stages of Method Study

  1. Select the operations or jobs to study – Select tasks on the basis of delays, safety issues, capacity problems, queues, idle-time, bottlenecks, quality problems, high costs, control difficulties.
  2. Record the facts about it – The method can be studied by observation, by interview or by experiencing the job and then recording it in suitable formats – process charts, travel charts, string diagrams, multiple activity charts, motion analysis charts.
  3. Examine these – The methods study can examine the recorded process by asking series of questions to identify possible alternative, more effective methods.

    4. Develop a new method – New methods require knowledge of the possibilities – new machinery, the effects of removing a stage in a process or re-allocating it to another process or person.

5. Install and implement it – New methods once finalized must be installed. A new method could be installed in one line while the existing method continues on other line – this reduces risk and offers scope for learning.

6. Maintain it – A new method needs new sequences of operator action and probably different perspectives. Every member of the operations team needs to be committed to the new method. The process chart needs to be up-dated with the new method and associated documentation modified. The new method should be formally reviewed and its performance compared against benchmark data.

 

Motion study is used to design a work station or work environment. This design includes the workplace layout and environment, the tooling and equipment (e.g., work holders, fixtures, hand tools, portable power tools, and machine tools).

 

Motion analysis helps to design:

1.      Work method

2.      Workplace layout

3.      Tools, and equipment, arrangement of tools and equipment

Principles of Motion Economy are used to design the above said based on three categories:

  •  Principles that apply to the use of the human body
  • Both hands should be fully utilized.
  • The two hands should begin and end their motions at the same time.
  • The motions of the hands and arms should be symmetrical and simultaneous.
  • The work should be designed to emphasize the worker’s preferred hand.
  • The worker’s two hands should never be idle at the same time.
  • Method should consist of smooth continuous curved motions rather than straight motions with sudden changes in direction
  1. Principles that apply to the workplace arrangement
  2. Principles that apply to the design of tooling and equipment

The principles of motion economy facilitates the industrial engineer to reduce the fatigue level in the operator by proper work station design. Fatigue level will be at lowest possible levels if the work station is designed within the “Normal Working Area” and does not exceed the “Maximum Working Area”.

Industrial Engineer uses flow charts and grid charts for process design, layout design etc. To cite a few flow charts that are commonly used for process design is material flow chart and for the layout design string diagram or travel chart is used. Operation flow chart allows the industrial engineer to visualize the sequence of operations or sub operations depending on whether the study is done at macro or micro level. Flow chart uses symbols to represent various activities involved in an operation.

 

Process chart helps the management to identify value-added and non-value added activities and by modifying or eliminating non-value added activities productivity of the industry can be improved upon. While a multiple activity chart helps to analyse utilization of more than one resource and arrive at a best way to utilize multiple resources. When a time scale is added to these flow charts they become grid charts and facilitate calculation of shortest possible time for performing a job.

 

Work Measurement

 

Work measurement is 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. There are various ways in which work may be measured and a variety of techniques have been established. The  basic procedure, irrespective of the particular measurement technique being used, consists of three stages;

  1. Analysis phase – job is divided into convenient components, known as elements. Each element should have a definite start and stop.
  2. Measurement phase – specific measurement technique is used to establish the time required by a qualified worker working at a defined level of performance to complete each element of work.
  3. Synthesis phase – various elemental times are added, together with appropriate allowances to derive the standard time for the completing the job.

Standard Time = Basic Time + Allowances

 

Allowances are commonly referred to as PFD Allowance – where P stands for personal, F stands for fatigue and D stands for unavoidable delay.

 

 

One of the major application area of industrial engineering is capacity planning. Capacity planning and management is more critical in make – to – order setup when compared to make – to – stock setup. Make –to-stock setup generally manufactures general products which are usually standardized and uses a standardized process and invariably has some inventory in form of finished and in-process goods. Capacity planning and management is not so critical in this case. In the make-to-order, goods are made as and when required by the customer and hence capacity planning is more critical. Calculation of standard time and scientific allocation of time for allowances is considered to be important. Standard time is extensively used in work planning in terms of machine, worker and material, scheduling and in estimating delivery time. Standard time also used in calculating cost of manufacture before actual commencement of production. This will give an idea to the management whether manufacturing of proposed product in predetermined specifications and quantity is viable or not.

 

Apart from Standard Time industrial engineering facilitates calculation of Key Performance indicators of the enterprise.

 

Some of Key Performance Indicators are:

  1. Man to Machine Ratio
  2. Cut to ship ratio
  3. Order to ship ratio
  4. Ontime Deliveries
  5. Average style change over time
  6. Right first time percentage
  7. Quality to production ratio
  8. Down time percentage

 

Each of thes KPIs play vital role on cost production and hence factory’s economic viability, factory’s efficiency, profit margin and factory reputation.

  1. Man to Machine Ratio. It is defined as total number of workers employed in the factory to total number of operational machines. If the workers are deployed only in productive work, then the ratio will be low. If the factory employs significant nuber of workers as quality checkers, helpers and material handlers which are considered to be non-productive work then man-to-machine ratio will be high. This will in turn help the management to take a call total number of workers and type of workers as more the number of workers more will be labour cost and cost of production.
  2. Cut to ship ratio: It is ratio between total quantity cut and total quantity actually shipped to the customer. If this ratio is above 1, it means the factory is cutting more quantity than actually shipped even though some excess quantity has to be cut to take care of defectives and rejections. at the same time excess cut quantity should not be too high.
  3. Order to ship ratio: This is the ratio between total order quantity received and total quantity actually shipped. This will give an indication to cost of poor quality which ultimately eats into profit margin.
  4. Ontime Deliveries: Number of ontime deliveries talks about company’s reputation.
  5. Average style change over time: Every time a style change over takes place production is stopped either to rearrange the machineries and / or to instruct the operators on new style. This is considered as down time of machines and too many style changes will increase the machine down time and hence bring down factory’s efficiency.
  6. Right first time percentage: Right first time percentage pertains to goods produced as per specifications and required quality without any defects. Less number of rejections leads increasein factory’s efficiency
  7. Quality to production ratio: Quality of product is an important factor. Normally in apparel industry quality is expressed in terms of Defectives per Hundred Units (DHU). More DHU means more time is spent on rectifying defectives and replacing rejections. This again reflects of percentage of ontime deliveries and cost of poor quality.
  8. Down time percentage: Down time is machine idle time which could be due to number of reasons like waiting for material, waiting for instructions, machine breakdown etc.

 

Industrial Engineering has numerous other applications in apparel industry like operator performance analysis, bundle analysis, Work in progress (WIP) analysis. Another major application of industrial engineering in apparel industry is for Line Balancing especially in a piece rate factory. Need for line balancing occurs due to various reasons:

  1. Waiting for material – poor planning, too much of rejections in fabric inspection and cutting
  2. Imbalance in operator efficiency – variation in work content, variation in operator skill level
  3. Imbalance in output of successive machines – targets not matched or insufficient machineries, imbalance in operators’ skill level.

Line Balancing involves the following steps:

  1. Capacity Study
  2. Target setting

Target = Total no.of operators X 60/Garment SAM

  1. Identification of Bottlenecks
  2. Elimination of Bottlenecks

This is done in number of ways:

  1. Clubbing operations with under utilization wherever possible
  2. Shuffling operators – more skilled workers at bottleneck areas where output is less than target and less skilled operators to operations where output is more than target.
  3. Reducing cycle time with automation, semi-automation, using workaids, simplifying work content.
  4. Improve work methods, work station ergonomics and work environment to reduce fatigue levels and thereby reducing fatigue allowance and variation in output levels in course of the shift.

Conclusion

 

Industrial engineering is an essential part of any industry and is truer for garment industry which is more labour intensive. In the present context of highly competitive environment keeping the cost of production low is of primary importance and helps apparel industry to offer competitive pricing. Industrial engineering helps the factory to achieve cost effectiveness.

 

 

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Web links

 

References:

 

  1. www.businessdictionary.com
  2. Prasanta Sarkar,  ‘Work  Study  and  Industrial  Engineering  Terms  and  Definitions’
  3. Sabya Sachi Roy, Subodh Kumar Ghosh, Ripon Chakraborty, “Application of Industrial Engineering in garments sewing floor”, Bachelor of Science in Textile Engineering Project Report, Department of Textile Engineering, Daffodil International University, Dhaka, Bangladesh, Jan 2012.
  4. R. Rathinamoorthy, ‘Industrial Engineering – A New Concept of Apparel Engineering’, www.fibre2fashion.com
  5. Telsang Martand,  ‘Industrial  Engineering  and  Production  Management’,  S.Chand  & Company Ltd., 1998
  6. Shankar, ‘Industrial Engineering and Management’, Galgo, 2000.