Chapter 9 - Productivity Analysis

Motion Study and Work Design

Motion Study Definition

the analysis of the basic hand, arm, and body movements of workers as they perform work

Work Design Definition

involves the methods & motions used to perform a task

What’s the primary goal of motion study?

a) increase machine efficiency

b) reduce equipment size

c) analyze hand, arm, and body movements to improve work

d) eliminate visual inspection

c) analyze hand, arm, and body movements to improve work

What are ‘therbligs’?

a) tools for measuring vibration

b) 17 basic motion elements used in manual work

c) components of lean manufacturing

d) names of standard workstations

b) 17 basic motion elements used in manual work

Which of the following is not an effective therblig?

a) reach

b) use

c) search

d) assemble

c) search

What is the purpose of pre-positioning (PP) in motion study?

a) grasp the object with both hands

b) place the object in a predetermined location for later use

c) orient the object during work

d) measure time for each task

b) place the object in a predetermined location for later use

Which of the following is considered an ineffective therblig?

a) Use

b) Release

c) Hold

d) Grasp

c) Hold

Why are smooth, continuous motions preferred over straight-line abrupt ones?

a) they look better

b) they require more energy

c) they are slower

d) they reduce lost time in starts and stops

d) they reduce lost time in starts and stops

Which principle advocates using momentum to assist worker?

a) minimize arm motion

b) use symmetry

c) employ natural rhythms

d) reduce muscular strain

d) reduce muscular strain

According to motion economy, which motion level is most efficient?

a) whole body

b) arm

c) wrist

d) finger

d) finger

What is micromotion analysis primarily used for?

a) cost estimation

b) designing jigs

c) analyzing short, repetitive tasks at the therblig level

d) measuring machine vibrations

c) analyzing short, repetitive tasks at the therblig level

What is one of the key goals of workplace arrangement?

a) increase paperwork

b) reduce worker breaks

c) minimize eye strain and movement

d) remove tools from the station

c) minimize eye strain and movement

Picture of 2 pencil is given: on left - pencil w eraser, on right - penciil w out eraser

Which is better based on the principles of Tools Design?

a) Left

b) Right

Left

Micromotion analysis is used for ?

repetitive tasks

Each therblig represents _____ and _____ spent by a worker to perform a task

time; energy

Best Method Analysis

• document and understand the current process —> detailed motion analysis

• create an improved process —> use principles of motion economy

  • challenge the current process

What are the principles of motion economy?

guidelines to help determine:

• work method

• workplace layout

• tools & equipment

What is the objective of using the principles of motion economy?

to maximize efficiency & minimize worker fatigue

What are the three categories of the Principles of Motion Economy?

Principles that apply to …

1. the use of the human body

2. the workplace arrangement

3. the design of tooling and equipment

What is the central theme of the principles of motion economy relating to:

the use of the human body

the use of the 2 hands & the allocagtion of the work between them

What is the central theme of the principles of motion economy relating to:

the workplace arrangement

utilizing the law of physics to assist in the use of hands/arms while working

What is the central theme of the principles of motion economy relating to:

the design of tooling and equipment

recommendations for using body members other than the hands and arms