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Flashcards in REVISION Deck (38):

What is Industrial Engineering?

Concerned with the


It draws upon specialised knowledge and skills 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 obtained from such systems.


Name the primary activities in IE

Selection of processes

Design of tools and equipment

Design of facilities: layout of equipment, buildings, machines

Design of control systems

Development of cost control systems

Development of wage incentive systems

Development of job evaluation systems

Development of data processing systems

Plant location


What is work made up of?

Work - An activity in which a person exerts physical or mental effort to complete a task.


Made up of

  • Task
  • Work elements
  • Basic motion elements


What is a method study?

Method study is the

systematic recording and examination

of existing and proposed ways of doing work,

as a means of

applying and developing easier and more effective methods and reducing costs.


What are the typical objectives of a method study?

Increase productivity and efficiency

- Reduce cycle time

- Reduce product cost

- Reduce labour content


Improve customer satisfaction

- Improve product quality

- Reduce lead times


Increase flexibility of the work system

Improve worker safety

More ergonomic work methods


What is the basic steps for completing a work study?

SELECT - work to be studied

RECORD - the relevant facts by observations

EXAMINE - the facts critically and in ordered sequence

DEVELOP - the most practical, economic and effective method

DEFINE - the new method so it can always be identified

INSTALL - it as standard practice

MAINTAIN - standard practice by regular checks


What are the main areas for selection?


Labour intensive operations

Operations with high material handling

Operations with high scrap

Movement over long distances

Repetitive operations

Prior to automation

H&S concerns


What are diagrams and charts widely used for? Name them.

Diagrams and charts are widely used to: improve understanding; facilitate communication.


SEQUENCE: operational charts, process charts

TIMES: multiple activity charts

POSITION and MOVEMENT: layouts and string diagrams


What are operational charts and what are the two types of operations?

Graphical representation of operations to produce a product

Two types of operation

1. Process and assembly

2. Inspection


What are process maps used for and what do they look like?

Process mapping techniques have been widely used to provide a detailed picture of the process or system of interest.


CYLINDER - beginning or ending point of a process

RECTANGLE - task or activity step

DIAMOND - decision point


What are process charts used for and what are the principal types?

Graphical representation of processing activities performed on or by someone.


Principal types

Material process chart - analysis of material

Worker process chart - analysis of worker


Describe the 5 symbols used to detail the work performed by a material or workpiece as it is processed through a series of operations







What is a two handed process chart?

Used for detailed analysis of operator at a work station

Each hand charted individually and to a greater detail than normal process chart

Meaning for conventional symbols is modified. ‘Inspection’ is omitted for ‘operation’


Operation – used for grasp, use, release etc. of tool, component or material

Transport – used for the movement of the hand to/from the work, tool etc.

Delay – used when hand is idle

Storage – designated ‘hold.’ Used when the hand is used as a holding fixture


What is an activity chart and what are the various types?

Activity chart is a list of activities of one or more subjects plotted against a time scale to indicate how much time is spent on ecah task.



Left/right hand activity chart

Worker machine activity chart

Gang (multi worker) activity chart


What is a multiple activity chart and why are they useful?

Activities of more than one subject are each recorded on a common time scale to show their inter-relationship.


Useful for analysing and improving operations especially where there are a number of interrelated activities involving several operators/pieces of equipment.


What is a string diagram and why is it useful?

Used when looking at the layout of the plant by plotting movements on a scale drawing. 

Useful to understand complex layouts.


What are the three categories of process/assembly operations?

Make ready - preparation

Do - operation/transformation

Put away - work is moved (includes inspection)


Aim is to maximise DO as these add value


What is the systematic questions asked when examining an activity?

the PURPOSE of the activity (elimination)

the PLACE where the activity is undertaken

the SEQUENCE of the activity

the PERSON who does the activity

the MEANS by which the activity is undertaken (simplify)


Examine with a view to




or SIMPLIFY the activity


What are the three parts of motion economy?

Use of human body

(both hands utilised, symmetric actions, curved actions, momentum, gravity)


Design of workplace

(stations for tools, gravity feed bins, located in max working area, arranged for best sequence of motion, lighting)


Design of tools

(use fixtures/jigs not hands, combine tools, operations simulataneously, mechanised and automated where possible)


What is included in standard operating procedures?

Procedure: description of work elements to perform task

Tools: list of tools

Layout: plan or photo of workplace arrangement

Checks: checks or inspections required

Set-up information


Benefits of SOP?

Reduce variations in operation time, quality

Basis for training

Allow variations to be easily identified

Fixed basis for further improvement


What is ergonomics?

Applied scientific discipline concerned with how humans interact with tools and equipment while performing tasks

Ergonomics seeks to provide a fit between people and the jobs they do


Physical ergonomics - why do we need to take breaks?

Metabolism - provide energy for vital processes, assimilate new organic material in body

Basal metabolism - sustain circulatory and respiratory functions (average 1 kcal/hr/kg of body weight)

Activity metabolism - energy concerned with physcial activity

Digestive metabolism


Recommended max. for mean energy expenditure of 8 hr shift

5kcal/min for male, 4kcal/min for female


This plus oxygen debt demonstrates need for breaks!


What is muscle endurance?

Muscle endurance defined as capacity to maintain an applied force over time

Ability to maintain maximum static force only lasts a short time

After about 8-10 mins a person can only apply about 25% of max static force at the start

Shows the importance of use of mechanical work holders, fixtures


What is Anthropometry and what are the design principles associated?

Anthropometry - empirical science concerned with the physical measurement of the human body



design for extreme individuals

design for adjustability

design for average user: last resort

design for different sizes


What is cognitive ergonomics and what are the guidelines for sensory reception?

Study of the capabilities and limitations of the human brain and sensory system while performing activities that have significant information processing content


Guidelines for sensory reception and perception


Redundancy – info using more than one sense

Stimulus variation: use of variable stimuli

Graphical displays



What is attention and what are te different types of it

Attention means keeping one’s mind on something. Involves mental concentration and readiness for such concentration



Selective attention: person needs to monitor multiple sources of information to perceive irregularities

Focused attention: person must cope with multiple input channels but focus on one

Divided attention: there are multiple stimuli and multiple tasks to be performed together

Sustained attention: must watch signal of interest over a long period of time


Name factors leading to boredom

Factors leading to boredom

Short cycle times

Low requirements for body movements

Warm environments

Lack of contact with other works

Low motivation

Low lighting


What are the guidelines for memory?

Guidelines for memory

Minimise demands on working memory

Exploit chunking (limit chunk size)

Increase frequency and recency of using info stored in long-term memory

Use memory aids


What are the factors affecting the difficulty and speed of response selection and execution

Factors affecting the difficulty and speed of response selection and execution


Decision complexity: more choices longer to make selection

Response expectancy: can process info you are expecting quickly

Compatibility: positive response should be consistent with one’s expectations

Trade-off between speed and accuracy: negative correlation

Feedback: learn from the effects of their actions


What are the factors affecting the physical work environment?

Visual environment and lighting

Auditory environment and noise

Climate control


What is the difference between luminous flux, luminous intensity and Illuminance?

Luminous flux – rate at which light energy is emitted in all directions from a light source (lumen)


Luminous intensity – luminous flux emitted in a given direction (candela)


1 cd isotropic point source of light radiates 4 pi lumens


Illuminance: luminous flux shining per unit area on a surface

Units: lux = 1 lumen per sq meter = 1^-2


E (illuminance) = l (luminous intensity) /d^2 (distance)


What are the permissible noise levels?

Sound intensity measured from listener’s perspective.

It is not a power measurement of the sound source

Could be measured as pressure. Intensity is measured relative to a reference pressure and converted to log scale called sound pressure level with the units decibel


Noise regulations specify actions at certain levels of noise, when averaged over an 8hr working day and also specify exposure to maximum noise (peak sound pressure)

For daily exposure averaging over 80 dBA employers must provide hearing protection if requested

For daily exposure over  85 dBA must provide and ensure it is used



What are the Physiological effects of noise

Startle response – due to sudden loud noise

Causes spontaneous muscle contractions, blinking eyes, head jerk movement

Hearing loss

Temporary threshold shift: hearing impairment of short duration

Noise induced permanent threshold shift: long term exposure to high noise level

Acoustic trauma: single exposure to high intensity noise can cause temporary or permanent hearing loss


What are the three noise abatement techniques?

Noise abatement at three locations

Source: quieter machinery, insulation

Receiver: use of ear plugs

Path between source and receiver


What are the four variables that affect climate of the workplace?

Air temperature


Air movement

Radiation from surrounding objects



Ways to reduce heat stress

Reducing heat stress

Administrative controls:

  • Water for workers
  • Frequent rest breaks
  • Limit time in hot environment
  • Work in shade not sun

Engineering controls

  • Provide air conditioning
  • Fans
  • Shield radiant heat sources
  • Wear protective clothing