Lecture 1 & 2

Question 1

Define Industrial Engineering

Answer 1

Industrial Engineering is concerned with the design, improvement, and installation of integrated systems of men, materials and equipment. It draws upon specialised 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.

Question 2

Define work

Answer 2

Work is defined as an activity in which a person exerts physical and/or mental effort to accomplish a given task or perform a duty.

Question 3

Describe the work triangle

Answer 3

• Work elements - Screwing/placing a gear etc.
• Basic motion elements - also known as Therbligs.
• Therbligs - 18 kinds of elemental motions used in the study of motion economy in the workplace.

Question 4

Define method study.

Answer 4

• Method study is the systematic recording and critical examination of existing and proposed ways of doing work, as a means of developing and applying easier and more effective methods and reducing costs.
• Other terms you may come across for methods study:
  • Methods engineering
  • Work simplification
  • Process re-engineering
  • Business process re-engineering

Question 5

What are the typical objectives of method study?

Answer 5

• Increase productivity and efficiency
• Reduce cycle time
• Reduce product cost
• Reduce labour content
• Improve customer satisfaction
• Improve product and/or service quality
• Reduce lead times and improve work flow
• Improve worker safety

Question 6

List out the basic steps of the Method study procedure.

Answer 6

The basic procedure for method study is as follows:

• SELECT - the work to be studied
• RECORD - all the relevant facts about the present method by direct observation
• EXAMINE - those facts critically and in ordered sequence
• DEVELOPE - the most practical, economic and effective method
• DEFINE - the new method so that it can always be identified.
• INSTALL - that method as standard practice
• MAINTAIN - that standard practice by regular checks

Question 7

In the Method study procedure: What work is choosen in the SELECT process?

Answer 7

• Obvious areas are bottlenecks - where a particular operation is restricting output, labour intensive operations, operations involving much material handling, operations with high scrap or wastage, etc. A pareto analysis of operations cost or labour requirement can help in the selection.
• other criteria
  
  • Movement over long distances
  • Repetitive operations
  • Prior to automation

Question 9

Draw an example of an operation chart.

Describe operation charts are, and the two types of operations.

Answer 9

• Graphical/Symbolic representation of the operations used to produce a product.
• Two types of operations:
  
  • Processing/assembly operations
    
    • Changing the shape, properties or surface of a workpart
    • Joining two or more parts to form an assembly.
  • Inspection operations
    
    • Checking the material, workpart, or assembly for quality or quantity.

Question 10

Identify some parts in the process that could changed to improve effieciency.

Answer 10

Question 11

What are process maps?

Draw a basic process map explaining the different symbols.

Answer 11

• Used to provide a detailed picture of the process or system of interest.
• Commonly used symbols for basic process maps
  
  • Rounded rectangle - Beginning/ending point of the process
  • Rectangle -Task or activity step
  • Rhombus - Decision point

Question 12

Draw an example of a Cross-Functional process Map.

Answer 12

Question 13

What are the two principal types of process charts?

Answer 13

• Material (or Flow) process chart - analysis of material or workpiece flow.
• Worker process chart - analysis of a worker performing a task.

Question 14

What are the five symbols for a flow process chart?

Answer 14

• Uses five symbols to detail the work performed on a material or workpiece as it is processed through a sequence of operations and activities.

Question 15

What are some issues you can see with this flow process chart?

Answer 15

Question 16

What is a two-handed process chart

Answer 16

• This is a derivative of the process chart and is used for the detailed analysis of an operator at a work station.
• The movements of both hands are charted invidividually and to a greater level of detail than on a normal process chart.
• The meaning of the conventional symbals are modified:
  
  • “inspection” is generally imitted as it is of the same form as “Operation”
  • delay - use when the hand is idle
  • storage - redesignated “hold” used when the hand is used as a holding fixture.

Question 17

What are activity charts and what are the different types of activity charts?

Answer 17

• A listing of the activities of one or more subjects (e.g. workers, machines) plotted against a time scale to indicate graphically how much time is spent on each activity.
• Types of activity charts:
  
  • Right-hand/left-hand activity chart (a.k.a workplace activity chart)
  • Worker-machine activity chart
  • Worker-multimachine activity chart
  • Gang activity chart (a.k.a. multiworker activity chart)

Question 18

Draw a table showing the different shading/colour formats for activity charts.

Answer 18

Question 19

Give an improvement for the process described by this Activity chart.

Answer 19

Question 20

What is a multiple activity chart?

Answer 20

• A chart on which the activities of more than one subject (worker, machine, or item of equipment) are each recorded on a common time scale to show their inter-relationship.
• The activities of each subject are recorded on a separae bar or column against the time scale.
• These charts are useful for improving operations where there are a number of interrelated activities involving several operatiors and pieces of equipment.

Question 21

What are layout charts/string diagrams?

Answer 21

• These are used when looking at the layout of plant and equipment. They differ from flow process charts by showing movements plotted on a scale drawing.
• String diagrams, while appearing crude, provide an excellent way of getting to grips with a complex layout.

Question 22

Show a better layout for the following string diagram.

Answer 22

Question 23

In the method study procedure: what is the first stage of examination?

Answer 23

• The activities recorded on the flow process chart fall into two main categories:
  
  • those where something is actually happening to the material under consideration, i.e. it is being worked upon, moved or examined.
  • those in which the material is not being touched, i.e. delay or storage.
• The activities in the first category may be further subdivided into three groups:
  
  • “MAKE READY” activities required to prepare the material or work and set it in position ready to be worked on.
  • “DO” operations in which some transformation is made to the material
  • “PUT AWAY” activities during which the work is moved from the workplace, this may include inspection

Aim to maximise the ratio of “DO” operations as these are the only things that add value to product.

Question 24

In the method study procedure: During examination what systematic takes place?

Answer 24

• All activities are subjected to a systematic questioning technique as follows:
  
  • the PURPOSE for which the activity is undertaken.
  • the PLACE at which the activity is undertaken.
  • the SEQUENCE in which the activity us undertaken
  • the PERSON by whom the activity is undertaken
  • the MEANS by which the activity is undertaken.
• Examine with a view to ELIMINATING, COMBINING, REARRANGING or SIMPLIFYING those activities.

Question 25

In the method study procedure: What are the 12 basic principles for the use of the human body in the DEVELOP stage?

Answer 25

1. Both hands should be used
2. Two hands should being/complete their movements at the same time.
3. Motions of the arms should be symmetrical and in opposite directions and should be simulatenous.
4. Work should be designed to emphasise the worker’s preferred hand.
5. The two hands should not be idle at the same time except at periods of rest.
6. Continous curved movements > straight line movements with sudden changes in direction.
7. Momentum should help worker, but reduced to a miniumum when it has to be overcome my muscular effort.
8. The method should take advantage of gravity instead of opposing it.
9. Rythm is essential to the smooth and automotic performance .
10. Hand and body motions should be made at the lowest classification possible.
11. The method should be designed to utilise the worker’s feet and legs when appropriate.
12. Work should be arranged so that eyes dont need to rapidly change focus.

Question 26

In the method study: In the DESIGN stage what are the 5 classifications of hand and arm motions?

Answer 26

1. Finger motions only
2. Finger and wrist motions
3. Finger, wrist and forearm motions
4. Finger, wrist, forearm, and upper arm motions
5. Finger, wrist, forearm, upper arm, and shoulder motions.

Question 27

In the method study procedure: In the DESIGN stage, how should the workplace be arranged?

Answer 27

• Definite and fixed stations should be provided for all tools.
• Tools and materials should be pre-positioned to reduce searching.
• Gravity, feed, bins and containers to deliver materials.
• Tools/materials and controls should be located within the maximum working area and as near to the work possible. Also arranged to permit the best sequence of motion.
• Provision should be made for adequate lighting, and the colour of the workplace should contrast with that of the work and thus reduce eye fatigue.

Question 28

In the method study procedure: In the DESIGN stage, describe the design of the different tooling and equipment.

Answer 28

• The hands should be relieved of all work of “holding” the workpiece where this can done by a jig/fixture.
• Two or more tools should be combined wherever possible.
• The hands should be relieved of work elements that can be performed by the feet.
• Multiple operations should be performed simultaneously rather than sequentially whenever possible.
• Manual operations should be mechanism/automated wherever feasible.
• Equipment desgiend for error avoidance.

Question 29

In the method study procedure: What is the DEFINE stage?

Explain the SOP

Answer 29

• Once designed, you need to DEFINE it so it can be identified.
• This is done with a Standard Operation Procedure (SOP), which should include:
  
  • Procedure: Description of the work elements to perform the task.
  • Tools: A list of the tools and gauges used at each stage in the procedure.
  • Layout: plan or photograph of the workplace arrangement
  • Checks: checks/inspections required during the procedure
  • Set-up information

Question 30

What are the aims of SOP?

(Standard Operating Procedure)

Answer 30

• The aim of Standard Operating Procedures is to ensure that tasks are always performed in the same way. This will:
  
  • Reduce variations in operation time
  • Reduce variantions in quality
  • Provide a basis for training new operations
  • Form a fixed basis for further improvement.

Question 31

In the method study procedure: Explain the point of the INSTALL and MAINTAIN method.

Answer 31

• Having DEFINED the improved method it is then necessary to:
  
  • INSTALL it as standard practice and
  • MAINTAIN that standard practice by regular checks.
• These stages aren’t discussed but are CRITICAL to the success of the process.