Methods exam 2

Pomodoro

Created by Francesco Cirillo

Time management technique: Estimate how many intervals; silence phone; 30 mins on / 5 mins off; after 4 intervals take longer break

Quote by who “A man who carries a cat by the tail learns something he can learn in no other way”

Mark Twain

Quote by who “Being a student is easy. Learning requires actual work.”

William Crawford

Quote by who “If you think education is expensive, try estimating the cost of ignorance.”

Howard Gardner

Quote by who “Smooth seas do not make skillfull sailors”

African Proverb

Quote by who “ Knowing is not enough; We must apply”

Bruce Lee

Quote by who “Every student can learn, just not on the same day, or the same way”

George Evans

Training is an intentional effort to improve performance by

helping employees acquire skills and knowledge required for work

Training is designed to

increase the rate at which employees learn and build skills

SRK Model: Skill Based Levels

Performance and decision making is at the subconscious level and is an automatic response to particular situations

• High expertise → Very fast response

SKR Model: Rule Based Level

Operating on familiar tasks but not expert at

• Pattern matching (from past experience): IF symptoms are X THEN problem is Y. IF problem is Y THEN solution is Z

SKR Model: Knowledge Based Level

The task is novel and people have limited experience

• No rules from past experience (MUST improvise in unfamiliar environments

• Forced to analytical problem solving process using conceptual information / theory

Training: On-the-Job Learning

Puts operator directly on a new job with no training (Sink or Swim approach)

Training: Written Instructions

Simple written descriptions of correct methods (IMPROVEMENT over On-the-Job learning, but ONLY for relatively simple operations)

Training: Pictorial Instructions

Pictures used with written instructions have proven to be very effective for training operators

Training: Videos

Movies can show the dynamics of the process

Training: Physical Training

Involves physical models, simulators, or real equipment. BEST for complex tasks

WEAVER’S KNOT

Learning Styles: Visual / Spatial

using pictures, images, and spatial understanding

Learning Styles: Aural (Auditory musical)

using sound and music

Learning Styles: Verbal (linguistic)

using words; both in speech and writing

Learning Styles: Physical (kinesthetic)

using body, hands, and sense of touch

Learning Style Models: Logical (mathematical)

prefer using logic, reasoning, and systems

Learning Style Models: Social (interpersonal)

prefer to learn in groups or with other people

Learning Style Models: Solitary (intrapersonal)

prefer to work alone and use self-study

Remission

Operator forgets something learned when away from the job

Skill remission

temporary decline or loss of previously acquired skills, knowledge, or learning performance

What can cause skill remission

• lack of practice

• mental fatigue or interference

Relearning is often quicker than initial acquisition

As production doubles, time/unit declines by 20%

As production doubles, time/unit declines by 20%

y=kxⁿ

• y = cycle time

• x = # cycles or units produced

• n = exponent of slope

• k = 1st cycle time

Learning Curve Calculation: y = kxⁿ

• 85% learning curve → n = -0.234

• Std. Time: 2.2 min

  • Part 1: 4.3 min

  • Part 2: 3.66 min

2.2 = 4.3(x)^-.234

x = 17.53 →→ 18 parts to reach standard time

Typical learning rates

• Large assembly work: 70-80%

• Welding: 80-90%

• Machining: 90-95%

• Typical learning rate = 70%

Learning Rate Coefficient: T_N = T₁C

T_N = # labor hours required to produce Nth unit

T₁ = # labor hours required to produce 1st unit

C = Leaning curve Coefficient

Learning Curve Calculation: y = kxⁿ

• A Korean shipyard required 125,000 labor hours to build the first

  of four tugboats ordered by your company for barge operations on

  the Mississippi River. The learning curve for tugboat production is

  assumed to be 75%

  • How many labor hours to produce 2nd and 3rd?

  • Labor cost $40/hr. What is Labor cost of 2nd and 3rd?

  • Total labor cost of all 4?

• 2nd: 125,000hrs * .75 = 93,750hrs → 93,750hrs * $40/hr = $3,750,000

• 3rd: 125,000hrs * .634 = 79,250hrs → 79,250hrs * $40/hr = $3,170,000

• All Boat Labor: 125,000hrs * 2.946 = 370,000hrs → 370,000hrs * $40/hr = $14,800,000

  • 2.946 comes from adding 1.0+.75+.634+.562

Stopwatch time study is a ________, where a stopwatch records the time for a worker to _________.

• direct work measurement method

• perform elements of a task for a # of cycles to obtain statistically valid measurements

  • and establish a reliable standard time

Cycle time

The time from start to start of units in production

Gemba

Go to the spot; know the actual situation

Actual Data

Considers delays, environmental conditions, fatigue, work pace, & elemental breakdown of the task

Standard Time

Amount of work by Qualified Employee working at Normal Pace & Effectively utilizing time where work is not restricted by process limitations

Time Study Procedure

Select timed task

1. Standardize the method of working

2. Select the operator

3. Record details

4. Break task into elements

5. Determine # of cycles needed

6. Time each element using stopwatch

7. Determine standard ratings

8. Calculate normal time

9. Determine allowances

Determine standard time

Reasons to study tasks / jobs

• Bottlenecks

• Improve Efficiency

• Compare two methods

• Change production rate

• New model

Types of elements to breakdown in time study

• Repetitive: occurs every work cycle

  • Picking up parts prior to assembly

• Occasional: May occur at regular or irregular intervals, but not every cycle

  • Adjusting machine settings, quality check

• Constant: basic time remains constant whenever performed

  • Switch machine on, Machine cycles

• Variable: basic time varies in relation to characteristics of product, equipment, or process

  • Sweep the floor

• Manual: Performed by worker

• Machine: Performed automatically, once started cannot be influenced by worker, except to terminate procedure prematurely (estop)

• Governing: takes a longer time than any other element performed

  • Turn a diameter on a lathe while gauging occasionally

• Foreign: observed element that does is not part of the operation

  • Dropping a part during assembly

Guidelines for picking elements:

• Try to pick an indivisible step: reaching, grab, alignment, tool use

  • find natural break points

• Pick small as possible; not less than .05 minutes (3 seconds)

  • can they be subdivided

• Better to have too many elements than too few

  • Elements that end in a sound are best

Observed Time

Time measured on stopwatch

Normal Time =

Observed Time * Rating

Standard time =

Normal time * (1 + allowances)

Standard performance is rated as 100%. Performance Ratings are

the step in the work measurement in which the analyst observes the worker's performance and records a value representing that performance relative to the analyst's concept of standard performance.” –Groover

Benchmark

A standard or a set of standards, used as a reference for evaluating performance or level of quality

Objective Rating: Structured comparison to normal pace

• It is "objective" because it relies on predetermined criteria rather than the analyst’s judgment alone.

• Goal: reduce subjectivity and improve consistency among time study analysts

Westinghouse System Ratings

Breaks performance into four factors:

• Skill – how well the job is done (dexterity, coordination).

• Effort – speed or pace (energy applied).

• Conditions – surrounding environment (lighting, temperature, tools).

• Consistency – steadiness of performance (few errors or delays)

• Each factor has a scale with plus or minus adjustments to a base rating. RATING is 1±0.ratings

Synthetic Rating

Instead of judging the worker’s speed directly, it uses predetermined time standards (like MTM or MOST)

Speed Rating based on the speed or tempo of operator’s output compared to a qualified worker’s

• Experience and judgment of the analysts are the criteria for determining the rating factor.

Effective Utilization

Maintaining a standard pace

Allowances: Accounted for planned interruptions or delays

Methods for developing std allowances

• Direct observation – requires observers to study two or three operations over a long time. Observers record the duration of and reason for each idle interval.

• Work Sampling Study – requires taking a large number of random observations, thus requiring only part-time, intermittent services of the observer

Personal Needs: interruptions necessary for the wellbeing of employee

5% allowance; bathroom/water fountain trips

Basic Fatigue: Energy expended to carry out work and alleviate monotony

4% normally; light work, seated, good working conditions

Variable Fatigue: Physical and psychological

Factors:

• Working conditions - noise, heat, humidity

• Type of work - posture, muscle exertion

• boredom

• Mental strain, precision work

Unavoidable delays:

• supervisor, dispatch interruption, machine / material faults

• Servicing; Quality check, tool change, model change, cleaning

• Material handling

Avoidable delay: Not included to determine standard

• social visit

• day-dreaming

• long breaks / early quits

• any unnecessary interruption

Allowance calculation:

• Move cart - 20 min

• COP end of shift - 5 min

• Tool change, 3 - 5 min each

• personal needs - 2%

• fatigue - 4%

• NT - 30 secs/unit

• 8hr = 480 min

• 40min/480min = 8.3% unavoidable

• 8.3+2+4 = 14.3%

ST = 30sec/unit * (1 + .143) = 34.4sec/unit

Element types

• Repetitive: occurs ever cycle

• Manual: depends on worker rate

• Constant vs variable: some elements vary cycle to cycle. ex. larger piece = more time

• Occasional: not every cycle

• Foreign: not part of job

Foreign elements: External to process that delay work

• when occur during element, record in Foreign Element List, give label, note in NT block of element

• Supervisor interrupt

• defective parts

• adjusting tools

• breakage

• dropped parts

• wiping sweat

If recorded miss change from element to next

Place M in W column

If operator skips element

Draw — through W column

Standard data:

• build it yourself ; history / calculations

• Buy a database

• books, handbooks, charts, nomograms, etc

Advantages: cost/time, consistency

Disadvantages: Availability, applicability, database $

Nomogram ; alignment chart: graphical calculating device

2D diagram designed to approximate graphical computation of a math function

How long would it take to turn 18in of 1-in bar stock on a lathe running at 300 ft/min & feed rate of 0.005 in/r

• T = L/F

• F=3.82*f*S / d

  • F= 3.82*.005in/r*300ft/min / 1in = 5.73in/min

• T=18/5.73 = 3.1minutes

How long should it take a welder to make a 3/8in root pass on a plate requiring 8ft of weld

Time = min/in weld*length(in)

• 3/8in → 0.067min/in

• Time = .067min/in×8ft*12in = 6.43minutes

Therbligs: basic motions or element actions

used to

• improve efficiency

• identify wasteful motion

Therblig 18 elemental motions

• Search, find, select

• Grasp, hold, transport loaded, transport empty

• Position, Assemble, Use, Disassemble

• Inspect, preposition, release load

• unavoidable delay, avoidable delay

• plan, rest

Therblig Motion Study

• Select Task: (short, repetitive, manual task)

• Record Task: (video or direct observation)

• Break into elements: (discrete action or micro-action. Micro-actions should be a change in purpose or motion)

• Assign Therbligs: (symbol and label right or left hand.

• Identify value-added vs non-value-added

• Analyze for improvements

• Develop improved method

Value Added (VA)

Changes form, fit, function, or features. Customer is will to pay for this change

Non Value Added (NVA)

Consumes time / resources without meaningfully changing product

TIMWOOD

• Transportation

• Inventory

• Motion

• Waiting

• Overproduction

• Overprocessing

• Defects

Therblig Classification

1. Keep: Motions required to perform operation ( transport empty, grasp, transport loaded, position, use, assemble, release, inspect)

2. Minimize: Motions that slow down type 1 (search, find, select, plan, prepostition)

3. Eliminate: motions that do not perform operation (hold, unavoidable delay, avoidable delay, rest)

Predetermined Time Study

Procedure that analyzes manual operations or methods into the basic motions needed to perform them and assigns each a predetermined time based on the motion and environment

ADA Timeline

• Civil Rights Act of 1964

• Voting Rights Act of 1965

• Civil Rights Act of 1968

• Rehabilitation Act of 1973

• Education of Handicapped Children Act (1975)

• Fair Housing Act Amended (1988)

• Americans with Disabilities Act (ADA) 1990

• ADA Amendments Act (2008)

ADA 1990: Makes it unlawful to discriminate in employment against qualified individuals with a disability

Prevent discrimination in:

• employment (title I)

• public service (title II)

• public accommodations (title III)

• Transport

• Telecommunications (title IV)

• misc title V

Protected under ADA

Impairment that substantially limits:

• hearing

• seeing

• speaking

• breathing

• walking

• performing manual tasks

• learning

• caring for oneself

• Working

Accommodation Cost Estimates

• 50%: less than $500

• 19%: nothing at all

• >80%: less than $1000

Disabilities: Role for IE

• develop functional job descriptions

• talks with EEO manager, HR, & Medical dept for employee placement

• safety & ergo analysis based on disabled employee’s limitations

• Recommend safety & ergo modifications to

  • machine tools

  • processes

  • facilities

  • environment

Universal design: The design of buildings, products, environments to make them accessible to people REGARDLESS of age, disability, other factors

Addresses common barriers by creating things that can be used by the maximum # of people possible.

• sidewalk ramps are essential for people with wheelchairs but used by all

7 principles of Universal Design

1. Equitable Use (design serves everyone -ex. dropped curbs)

2. Flexibility in Use (ex. adjustable height desks)

3. Simple and Intuitive Use (ex. Automatic door opener)

4. Perceptible Information (ex. unique symbols for gender-based restroom)

5. Tolerance for Error (ex. undo function in software)

6. Low Physical Effort (ex. touchless faucet / soap dispenser)

7. Size & Space for Approach & Use (ex. wide doorway / hallway to accommodate wheelchairs)

Predetermined Timestudy

• Foundations

  • Early 1900s Frederick Taylor; stopwatch TS

  • Frank & Lillian Gilbreth developed motion study & THERBLIGS

• Birth of PDTS

  • 1940s (MTM) Methods-Time measurement developed

  • Times assigned to basic motions

  • MTM variants to improve usability

• 1960s HB Maynard; MTM too detailed and time consuming

  • developed MOST

  • Faster than MTM - less accurate

MTM to MOST

• performance rating eliminated (times are at 100% NT)

• Measurements in TMU

  • 1hr = 100,000TMU

  • 1sec = 27.8 TMU

  • 1TMU = .036 sec

Maynard Operation Sequence Technique

• Work: displacement (movement) of mass or object

  • Work = Force*Distance

• “MOST is a system to measure work; therefore, MOST concentrates on the movement of objects.” - Zandin

  • used to analyze work and determine the NT