Chapter 10 - Productivity Analysis

Work Measurement

What is a Work Standard?

a specification for performing a unit of work

What does a work standard address?

• how the work is to be performed (method)

• how long it should take (time)

• what the outcome should be

What term is interchangeable with “work measurement” ?

time study

Defn of time study / work measurement

how long it takes

What is the objective of the work measurement?

to determine a standard time for the task

standard time definition

amount of time that should be allowed for an average worker to process one unit using the standard method and working at a normal pace under specified work conditions with capable supervision

When are time standards benefiical?

• low productivity

• repeat orders

• long production runs

• repetitive work cycles

• short cycle times

What do time standards determine?

• workforce requirements

• capacity limitations

• a base for wage incentives

What are the methods to determine time standards?

• Estimation

• Historical records of previous production runs

• Work measurement techniques:

  • Direct Time Study (DTS)

  • Predetermined Motion Time System ( PMTS )

  • Standard Data Systems (SDS)

  • Work Sampling

Direct Time Study (DTS)

direct observation of a task using a stopwatch or other chronometric device to record the time taken to accomplish the task

Predetermined Motion Time System (PMTS)

system that relies on a database of basic motion elements such as reach, grasp, and move that are common to nearly all manual industrial tasks

Standard Data Systems (SDS)

a compilation of normal time values for work elements used in tasks tat are performed in a given facility

Work Sampling

random sampling techniques to study work situations so that proportions of time spent in different activities can be estimated w a defined degree of statistical accuracy

pre-reqs for valid time standards

everything has to be “average”

standard method

procedure that has been determined to be the optimum method for procesing a unit

standard method should include the following details abt how a task is performed:

• procedure ( actions and motions ) used by the worker

• tools & equipment

• workplace layout

• irregular work elements

• working conditions

• setup

Specified Work Conditions include:

• tools, materials, and equipment needed to perform the work

• workplace layout

• prescribed process times, feed rates and equipment speeds

• environmental conditions

  • light

  • temp

  • accessibility of work station

An average worker has a performance level of …

100%

What are the two types of delays?

1. Avoidable

2. Unavoidable delay

Avoidable Delay

• can be anticipated and prevented

• NOT included in the standard time

• ex) scheduled m/c downtimes, non work due to temporary shortage of materials

Unavoidable Delay

• predictable

• may occur at random times

• ADDED to standard time

What are the two constant allowances in ILO?

1. personal allowance —> 5%

2. basic fatigue allowance —> 4%

What are the 3 ways in which PFD percentages can be applied?

1. entire plant receives one Apfd (most common)

2. each department has its own Apfd

3. each job has its own Apfd

What are the Direct Time Study Steps?

1. Preparation Work & Personnel Involved

2. Elemental Analysis

3. Determine # of cycles

4. Rating

5. PFD determination

6. standard time

In DTS’s guidelines for construction, there is a tip to keep manual and machine elements separate. Why?

machine times are less affected by ratings

(manual elements depend on the speed of the worker AKA has a rating)

What are the 3 steps to determining the # of cycles needed for a time study?

1. specify a confidence level

2. state a desired accuracy range

3. calculate a value for the sample size

Snapback Measure

DTS method where a stopwatch is reset to zero at the start of each work element

Continuous Measure

DTS method where the stopwatch runs continuously throughout the entire work cycle, recording the total time without resetting between elements

If the overall study is repetitive and less than 30 minutes,

do you rate the elements or the entire study?

rate the entire study

If there are significantly different elements,

do you rate the elements or the entire study?

rate the elements separately

If the study is longer than 30 minutes,

do you rate the elements or the entire study?

Rate the parts of the study separately

What are the two ways to get a rating?

1. Speed Rating

   1. you only consider the rate of accomplishment of work per unit time

2. Westinghouse Rating System

What are the 4 key dimensions to the Westinghouse Rating System?

1. Skill: proficiency at following a given method

2. Effort: demonstration of the will to work effectively

3. Conditions: how they affect the operator ( not the operation )

4. Consistency: lack of variation in times

** 0 —> D —> is average

Hawthorne Effect

phenomenon where individuals alter or improve their behavior simply bc they are aware they are being observed

Predetermined Motion Time System (PMTS)

work measurement technique whereby times established for basic human motions are used to build up the time for a job at a defined level of performance

PMTS is also known as

PTS

When you hear PMTS or PTS, what should you think of?

Therbligs

PMTS includes motions such as the following four:

1. reach

2. grasp

3. move

4. release

What is a popular example of predetermined motion time system?

Maynard Operation Sequence Technique (MOST)

MOST (maynard operation sequence technique)

• time ranges are predetermined for basic types of movements

• tables are set up to allow applicators to select time values and apply them to work methods

What is a benefit of MOST?

• eliminates having to record time from scratch

• eliminates the need for subjective performance rating

• fast to apply

• accurate

• consistent results

What is MOST based on?

• concept that work can be viewed as a movement of objects

• idea that the movement follows consistently repeating patterns

What are the 4 MOST Work Measurement Systems?

1. BasicMOST

2. MiniMOST

3. MaxiMOST

4. AdminMOST

BasicMOST

• most common!

• typically used for:

  • operations that are ‘medium cycle’ aka a few sec. to ~ 10 min

  • repetitive and non-repetitive operations

MiniMOST

• produces very detailed & precise analysis

• typically used for operations that:

  • are ‘short cycle’ ( approx 20 sec or less)

  • are highly repetitive; occur frequently

  • feature very little variation

MaxiMOST

• typically used for setups, heavy assembly, maintenance or utilities

• ‘longer cycle’ operations ( 2 min to several hrs)

• operations that are non-repetitive or vary widely from cycle to cycle variations

AdminMOST

• useful in analyzing administrative and clerical operations

What are some examples of AdminMOST

• using a keyboard or keypad

• handling letters/papers

• making copies

What are the 2 novel features of the MOST system?

1. the times reflect 100% performance level

2. it’s method sensitive

   1. can readily determine opportunities for improvement

What are the three types of movement of an object in MOST?

1. General move - picked up and moved freely through space

2. Controlled move - moved over a restricted path, bc of contact w or connection to another surface

3. Tool Use - combo of GM and CM

What is a standard data system (SDS) in work measurement?

a database of normal time values used to establish time standards for tasks composed of similar work elements

• data is collected over yrs of motion & time study

Where are the normal time values for the work elements usually compiled from?

previous direct time studies (DTS)

A standard data system (SDS) is almost always what?

custom-engineered & delivered for the facility

SDS advantages

• increased productivity in setting standards

• capability to set standards before production

• avoids need for performance rating

• consistency in the standards

• inputs to other info systems

SDS disadvantages

• high investment cost

• source of data must be present

• methods descriptions —> documentation required

• Risk of improper applications

What is work sampling?

the process of making sufficient random observations of an operator’s activities to determine the relative amount of time the operator spends on various activities associated with the job

Work sampling is the same as ?

activity analysis

What are work sampling applications?

• machine utilization

• worker utilization

• allowances for time standards (assessments of delay components in PFD allowance factor)

• time standards

work sampling is appropriate when there is ___ subjects.

multiple

Is work sampling appropriate when there are repetitive work cycles or non-repetitive work cycles?

non-repetitive

Which of the following is not part of the PFD allowance?

• A) personal time

• B) fatigue time

• C) delay

• D) machine cycle

D) machine cycle

In a snapback timing method, the stopwatch is:

• A) Never reset

• B) Reset at the end of the full cycle

• C) Reset to zero after each element

• D) Used only for irregular elements

c) Reset to zero after each element

Which component is not included in the standard time calculation?

• A) Observed Time

• B) Rating Factor

• C) PFD allowance

• D) Equipment Depreciation
  

D) Equipment Depreciation

Who is typically involved in conducting a time study?

• A) Analyst only

• B) Supervisor and Analyst

• C) Analyst, Employee, Supervisor, and Union Steward

• D) Employee only

C) Analyst, Employee, Supervisor, and Union Steward

What does the rating factor represent?

• A) Fatigue level of the worker

• B) speed of the machine

• C) Worker performance compared to standard pace

• D) Standard deviation of cycles

C) Worker performance compared to standard pace

Which of the following is true about continuous time measurement?

• a) stopwatch is reset after every element

• b) used only for irregular tasks

• c) stopwatch runs continuously through the cycle

• d) can’t be used with electronic stopwatches

c) stopwatch runs continuously through the cycle

In the Westinghouse rating system, ‘Conditions’ refer to:

• A) physical condition of the machine

• B) operator’s health

• C) environmental factors affecting the operator

• D) fatigue level of the operator

C) environmental factors affecting the operator

The Hawthorne Effect implies:

• A) Workers always perform at maximum efficiency

• B) Workers improve performance when observed

• C) Workers ignore time study observers

• D) Observation reduces productivity

B) Workers improve performance when observed

What does PMTS rely on?

a) worker opinions

b) historical data

c) random guesses

d) basic motion elements

d) basic motion elements

What is the ‘one best method’ principle?

• a) most popular way

• b) most expensive way

• c) safest and quickest way

• d) easiest way

c) safest and quickest way

What defines an average worker?

a) untrained

b) under-achiever

c) super-performer

d) average skill and effort

d) average skill and effort

What is the purpose of allowances in time standards?

a) to reduce productivity

b) to confuse workers

c) to increase stress

d) to compensate for lost time

d) to compensate for lost time

What is the application speed ratio?

a) manager’s efficiency

b) time to set a standard

c) worker’s speed

d) customer’s satisfaction

b) time to set a standard

What is work sampling used for?

a) To confuse workers

b) To increase costs

c) To estimate time proportions

d) To set time standards

c) To estimate time proportions

What is the function of time standards?

a) to plan and control

b) to reduce quality

c) to increase costs

d) to confuse workers

a) to plan and control

What is the purpose of a standard method?

a) to reduce productivity

b) to ensure quality output

c) to confuse workers

d) to increase costs

b) to ensure quality output

What is the main purpose of using a PMTS like MOST?

a) to improve marketing strategies

b) to replace the need for tools

c) to assign standard times using motion data

d) to eliminate manual labor

c) to assign standard times using motion data

Which of the following is not a commonly used PMTS?

a) MOST

b) Work-factor

c) MTM

d) TMSP

d) TMSP

What are the 3 phases in a General Move sequence model in MOST?

a) Grasp, Move, Drop

b) Start, Work, End

c) Get, Put, Return

d) Pick, Carry, Place

c) Get, Put, Return

A common limitation of work sampling is:

a) requires performance rating

b) always requires a stopwatch

c) can be confusing due to underlying stats

d) cannot be used for multiple subjects

c) can be confusing due to underlying stats

In a work sampling study, what does the symbol p^ (hat) represent?

a) population mean

b) estimated proportion of time spent on a specific activity

c) # of subjects in the study

d) total observation time

b) estimated proportion of time spent on a specific activity

Which of the following is NOT typically a suitable condition for using work sampling?

a) long cycle times

b) non-repetitive tasks

c) multiple subjects

d) highly repetitive, short tasks

d) highly repetitive, short tasks

What is the primary purpose of work sampling?

a) to determine average machine speeds

b) to continuously record an operator’s actions

c) to estimate the proportion of time spent on various activities

d) to design new work methods

c) to estimate the proportion of time spent on various work activities

What controversial step in DTS does SDS avoid?

a) elemental breakdown

b) performance rating

c) method documentation

d) machine cycle timing

b) performance rating

Which of the following is a disadvantage of SDS?

A) it can’t be used for any production process

B) universally transferable across all plants

C) requires a large database of prior time studies

d) eliminates need for time standards

C) requires a large database of prior time studies

One key advantage of using an SDS is?

a) eliminates need for method documentation

b) reduces cost and time of developing standards

c) provides real-time data during production

d) requires no historical data

b) reduces cost and time of developing standards

What is the unit of time measurement used in MOST?

time measurement units (TMUs)

In the MOST system, how is time calculated from TMUS?

TMU * 0.036 = seconds