Basic Theoretical Idea Of Industrial Engineering

TNZ Apparels Ltd.

Definition of work study

Work study is the systematic examination of the methods of carrying on the recourse and to set up standard of performance for the activities being carried out.

Quality of work study practitioner

Education with matriculation better skill a university education, preferably in the

engineering or business fields.

Objective of the work study

•Simplify or modify the operation to reduce unnecessary work.•Increase production or productivity •Setting time standard.•Reduce cost by most effective usage of inputs.•Improvement of condition which involve an element of excessive fatigue or danger.•Improve Quality.•Evaluation of human work.

What is the input?

•Land and building.•Materials(That can be converted into product)•Energy (power) Electricity, oil, solar power etc.•Machine and Equipment: (For operational activities, transport, heating, air, and conditional office equipment).•Man power recourse (man power).People how are tried to perform operational activities.In Words – Man, Machine, Materials, Money, Method.

What is our goal? & What can we do

To increase company profit.Savings means to stop the unnecessary things of the factory is as,

•Manpower: Extra manpower release •Over time: Extra time reduce•Maximum utilization of inputs.

What are the barriers between W.S.O and factory

•Workers not support.•Sometimes production staff does not support.•Sometime they can say “what you know”•Sometime they blame.

Techniques of work-study

.Work measurement (time it takes to the job)

Method study (better way to do the job)

Work-study

Higher Productivities

Method study

Work plan engineering.Motion study.Minimum work plan.Maximum work plan.

Work measurement

Time study.GSDSew easy.Capacity study.Historical dataAnalytical Estimating.

Definition of method study & objective

Method study is the systematic recording and critical examination of way of doing things in order make improvements.

•Simply the task.•Eliminate unnecessary motions.•Reduced inherent work content.•Engineering the production

Definition of work measurement & objective

Work measurement is the application of techniques design to establish the time for a qualified worker to carry out a task at a defined rate of working.

•Measure work content.•Determine the time.•Key to scientific measurement

Advantages of work measurement

•Set target.•Calculate efficiency.•Determine cost.•Man power allocation.•Production planning& control.•Inactive schemes.

Work measurement techniques

•Time study.-directly observing an operator.•Pre-determined motion time study system (pmts).-analyzing the motion used to carry out the activity.•Analysis the past record.-using previous record studied available in the factory.

Procedure of method study:(SREDEDIM)

•Select: The job to be studied.•Record: By collecting data or direct observation.•Examine: By challenging purpose, place sequence & methods of work•Develop: New method drawing on contribution of those concerned.•Evaluation: Result of different alternative solution.•Define: New methods & present it.•Install: New methods and train person in applying it.•Maintain: Establish control process.

Motion economy

•Reduce the number of motions.•Reduce the distances moved.•Reduce the eye shaft.•Simplify grasp.

•Toss dispose rather than place dispose.•Best use of both hands.•Encourage rhythm.•Promote natural pasture & movements

Use of human body

•Both hands same time.•Both hands not be idle.•Motions of arms simultaneous.•Continuous curved movements are preferred.•Eye movements are confined to a comfortable area, without the need frequent chances of focus.•Eye-hand co-ordination.•Order of movements natural of rhythm.•Hand and body motions lowest classification.

Productivity

Productivity is ratio of input and output .productivity is needed to reduce cost of product.

Productivity= Input

Output

SMV (Standard Minute Value)

•Definition: SMV is the time taken by a qualified worker to perform a specified task in a defined level of performance.

• SMV = Basic time x allowance•Basic time = Observed time x rating%

Use of SMV

•To calculate the individual operator target.•To calculate the section target.•For man power allocation.•For product costing.•For production planning.•Evaluate the performance.•For set the incentive levels.

Fabric manufacturer

There are three types of fabric•Woven•Knit•Non woven

SMV

•Standard minute value.•How to calculate SMV?•What are the methods to calculate SMV?

Time study PMTS(Predetermine motion time study

How to calculate efficiency?

(No of operator + helper)* working timeX 100

Formula:

SMV X no of good garment

Reason of ineffective time

•Excess product variety.•Lack of standardization.•Design change.•Bad planning.•Lack of fabric & accessories.•Badly maintained machine.•Accident.•Poor service.•Absence, lateness, laziness.•Talking•Carelessness•Accidents due to carelessness.

Time study

Definition of time study: Time study is a work measurement techniques for recording the time of performing a certain specific job or its elements carried out under specified conditions and for analyzing the data so as to obtain the time necessary for an operation to carry out at a define rate of performance.

How to do time study

•Stand diagonally behind the operator about 1.5-2.0meters.•Take more than 20 observations.•Record relevant detailed about the method and the machine.

Before starting a time study

•Method study should be done.•Method study produces the required quality.•For new methods plenty of time should give to settle down.•Operator should be rate between 70%-110%.•Inform the supervisor before start.•Operator should not be disturbed during the study.•Ensure operator gets enough supply.

Arrangement of work place

•Definite and fixed location.•Pre position reduces reach.•Gravity feed.•Tools and materials, best sequence of motions.•Drop deliveries whenever possible.•Chair height of the work place & comfort.•Color contrast with that of the work & reduce eye fatigue.

Steps of time study

•Obtaining and recording all the information available about the job the operative and surrounding condition which is likely to affect the carrying out the work.•Recording a complete description of the method breaking down the operation into elements. (Break down the elements).•Examining the detailed breakdown to ensure that the most effective method of motions is being used and determining the sample size.

Steps of time study

•Measuring with a timing device (stop watch) and recording the same time taken by the operation to perform each elements of the operation.•At the same time assessing the effective speed of the working of the operator relative to the observes concept of the rate corresponding to standard rating.•Convert the observed time to basic times (basic time calculation).•Adding necessary allowance to the basic time.•Determining the standard time for the operation

Definition of rating

Rating is the assessment of the workers rate of working relative to the observer’s concept

of rate corresponding to standard place.

Why need rating

•Standard worker is not available all the time.•Different people take different times.•To compare the observed worker with a qualified worker.•To convert the observed time to a time a qualified worker would likely to take.

How rating can be done

•Establish in mind how standard worker should work.•Compare the effective needs of the observed worker with standard worker.In terms of

Skills: The techniques apply to perform the job.Effort: Expression of the will to work efficiency.

Ratings

50 : Very slow - not interest75 : steady –unhurried100 :brisk –businesses like (standard)125 : Very fast – above average150 : Outstanding- unusual

What is an element?

An element is a distinct part of a specified job selected for convenience of observation measurement and

analysis.

Why break the operation into elements

•To give a systematic detailed specialization of work.•To identify subsequent omissions or insertions elements.•Operation may not work at the same place throughout the operation.•To extract the time for certain parts.•To keep the concentration of the time study officer.

Types of elements

•Repetitive elements: Repetitive elements are elements which are occurring every work cycle of an operation.

•Occasional elements: Occasional elements are an element which does not occur is every work cycle of an operation but which may occur at regular or irregular intervals.

•Constant element: Constant element is an element for which the basic time remains constant whenever it is performed.

•Variable elements: Variable elements are elements for which the basic time varies in relation to some characteristics of the product equipment or process.

Types of elements

•Machines elements: Machines elements is an elements performed automatically by any process physical, chemical or otherwise that once standard cannot be influence by worker except to determinate it prematurely.

•Governing elements: Governing elements is an elements occurring a longer time with in a work cycle than that of any other elements which is being performed.

•Foreign elements: Foreign elements are elements observed which does not form a part of the operation being studies.

How elements are selected?

•Easily identifiable beginning and ending (break point).•As short as can be conveniently timed (between 6.30 sec).• Re present naturally unified distinct segment of operation.•Separate machine and manual elements if possible.•Elements which do not occur every cycle should be timed separately before starting a time study.

Standard Performance

•Standard Performance is the rate of output which qualified workers will naturally achieve without over exertion as an average over the working day or shift. Provide that they know adhere to the specified method and provided that they are motivated to apply themselves to their work.This performance is denoted as 100 on the standard rating and performance scales.

Qualities a qualified worker

•Achieve smooth & consist movements.•Acquired rhythm.•Responds more rapidly to signals.•Anticipates difficulties and more ready to overcome them.•Carries out the task without giving the appearance of conscious attention and there for more relaxed.

Symptoms of skilled workers

•Avoidance of all unnecessary motions.•Shortest path of movements.•Sureness of touch and methods.•Smooth rather than jerky movements.•Consistently stick to the best methods.•Consistent cycle time.•Intelligent anticipation of the next move.

Symptoms of poor skills

•Lack of rhythm.•Inconsistency.•Jerky movements.

Standard worker (qualified worker):

A qualified worker is one who has acquired the skill; knowledge and other attributes t carry out the work in hand to satisfactory standards of quality, quantity and safety.

Approach to the worker

•First approach the supervisor before the operator.•Always be polite.•Ask permission to do the work study.•Stand in fall view of the operator.•Thanks the operator once the test is completed.•Make the operator feel relax.

Machine bed type

•Flat bed machine•Raised bed machine•Cylinder bed machine•Side bed machine•Post bed machine

Line balancing

•Thread same or not(color)•SPI•Needle type.•Needle distance.•Attachment use or not.•Operator skills.•Consider for the machine feed.

Stitch Types

As per the ISO classification there are mainly 6 stitch classes-

•Class -100 chain stitch •Class -200 hand stitch•Class -300 lock stitch•Class -400 multithread chain stitch •Class- 500 over edge chain stitch•Class -600 covering stitch

Class -100: chain stitch

Each loop is interconnected with the following with the same thread. Opposite side of the seam look different. This stitch type can be very easily unlocked by running back from the last stitch to the first. The seam is generally quite extensible. It is often used for temporary stitching.

Class 200: Hand stitch

Formed by single threads being passed completely from one side of the material to the other. The thread is held by the material originally made by hand, some of them can now also be formed by m/c.

Class 300 lock stitch

Formed by two different thread systems. A needle thread introduced from one side of the material is interlaced with and under thread supplied from a spool from the other side. The stitch is different to unpick and both side have the same appearance generally, lock stitch are less extensible then chain stitch seam. This type finds the widest application. Two or more thread lock stitch using needle thread and one bobbin thread.

Class 400: Multithread chain stitch

This also formed two thread systems. The loops of the needle thread are drawn all the way through the material and they are interconnected on the under side by thread supplied from a lopper.Top and bottom side have a different appearance. The stitch can easily be unpicked is quite extensible special applications are elastic cross over seams in knitted fabric and seam which have to be flat.Multi thread chain stitch using one or more needle thread and one or more loopers thread.

Class 500: over edge chain stitch

Over edge chain stitch are formed from one or more needle or lopper. Needle thread loops are taken all the way through the materials and interconnected with themselves or with other thread. At least one thread system passes around the edge of the materials. Over edge chain stitch of various types are used to neaten and to bund the cut edge woven and to knitted materials.Multithread over edge chain stitch using needle thread and lopper thread.

Class 600 covering stitch:

This stitch types is generally formed from three thread systems. The over thread lie on the top surface and are held in place by the needle threads which in turn are interlaced on the back of the seam by the lopper threads. They are used specially for making flat extensible seam in knit fabric.