Productivity and Quality Management Lecture 14.
57
-
Upload
nelson-horton -
Category
Documents
-
view
217 -
download
2
Transcript of Productivity and Quality Management Lecture 14.
Productivity and Quality Management
Lecture 14
• Productivity improvement has emerged as one of the top issues.
• Significant productivity programs launched in many businesses.
• In oil and gas industry, challenges to productivity continue to gain significant attention and hopes
Last Lecture Summary:Oil & Gas productivity
Last Lecture Contd.
Summary
• Productivity Improvement in Oil and Gas• Factors that improve productivity in Oil and
Gas:1). Integrating Automation2). Introducing Smart business processes3). Improving safety4). Risk Mitigation5). Innovations6). The Human element
Motion and Time Study (MTS)
WORK SYSTEMS
HISTORY OF MOTION AND TIME STUDY
Frank B. Gilbreth, Lillian M Gilbreth-1885, he begun to develop motion study. Gilbreth invented motion study designed to determine the best way to complete a job
Frederick W. Taylor-1881, he started to develop time studyTaylor designed Time Study; it measures how long it takes a worker to complete a task.
WorkMeas.mnt
MethodsDesign
MethodologyOutline of MTS • Develop System
– Design work methods (sequence of operations and procedures) that make up the preferred solution
– Find better methods for work• Standardize
– Form written standards for operations
• Time Standards– Determine a standard time for
each operation• Training
– Train the operators
Develop System
Standardize
Time Standards
Training
Defining Work Systems
Work• Is our primary means of livelihood• Serves an important economic function in the
global world of commerce• Creates opportunities for social interactions
and friendships• Provides the products and services that
sustain and improve our standard of living
Defining Work Systems• Work consists of tasks– Tasks consist of work
elements• Work elements consist of basic
motion elements
Defining Work SystemsTask• An amount of work that is assigned to a worker or for which a
worker is responsible– Repetitive task – as in mass production– Non-repetitive task – performed periodically, infrequently, or only
onceWork Element• A series of work activities that are logically grouped together
because they have a unified function in the task– Example: assembling a component to a base part using several nuts
and bolts
Defining Work Systems
Basic Motion Elements• Actuations of the limbs and other body parts – Examples:
• Reaching for an object• Grasping the object• Moving the object• Walking • Eye movement
– A work element consists of multiple basic motion elements
1.3 Defining Work Systems
• “Time=Money”? How?– New product introduction – Product cost – Delivery time – Overnight delivery– Competitive bidding– Production scheduling
• Increase profit using less time!
Defining Work Systems
• Importance of Time in Work– Time is the most frequently used measure of work
• How many minutes or hours are required to perform a given task?
– Most workers are paid by the time they work• Hourly wage rate • Salary
– Workers must arrive at work on time– Labor and staffing requirements computed in units of time
Defining Work Systems
• A work system is a system consisting of humans, information, and equipment designed to perform useful work– Contributes to the production of a product or
delivery of a service– Examples:• Worker operating a machine tool in a factory• Robotic welding line in an automobile plant• A receptionist answering incoming phone calls
Defining Work Systems
Productivity
Production as a function in EconomicsQ=f(K,L)• Q: Output, K: Capital, L: Labor• Is there a way to change function f with a
better function g?• Better Function=Higher Productivity
ProductivityProductivity• The level of output of a given process relative to
the level of input• Process can refer to – Individual production or service operations– A national economy
• Productivity is an important metric in work systems because– Improving productivity is the means by which worker
compensation can be increased without increasing the costs of products and services they produce
Productivity
Labor Productivity• The most common productivity measure is labor
productivity, defined by the following ratio:LPR =
– LPR = labor productivity ratio– WU = work units of output– LH = labor hours of input
LH
WU
Productivity
Labor Productivity Index •Measure that compares input/output ratio from one year to the next
LPI =
– LPI = labor productivity index– LPRt = labor productivity ratio for period t
– LPRb = labor productivity ratio for base period
b
t
LPR
LPR
b
t
LPR
LPRb
t
LPR
LPR
Example• During the base year in a small steel mill, 326,000
tons of steel were produced using 203,000 labor hours. In the next year, the output was 341,000 tons using 246,000 labor hours. Determine: (a) the labor productivity ratio for the base year, (b) the labor productivity ratio for the second year, and (c) the productivity index for the second year.
Productivity
Solution(a) In the base year, LPR = 326,000 / 203,000
= 1.606 tons per labor hour(b) In the second year, LPR = 341,000 / 246,000
= 1.386 tons per labor hour(c) Productivity index for the second year
LPI = 1.386 / 1.606 = 0.863 • Comment: No matter how it’s measured, productivity went
down in the second year.
Productivity
Productivity
Labor Factor in Productivity • Labor itself does not contribute much to
improving productivity • More important factors:– Capital - substitution of machines for human
labor– Technology - fundamental change in the way
some activity or function is accomplished
Productivity
Horse-drawn carts
Steam locomotive
Telephone operator
Manually operated milling machine
Railroad trains
Diesel locomotive
Dial phone
Numerically controlled (NC) milling machine
Productivity
Measuring Productivity • Not as easy as it seems because of the
following problems:– Nonhomogeneous output units – Multiple input factors • Labor, capital, technology, materials, energy
– Price and cost changes due to economic forces– Product mix changes • Relative proportions of products that a company sells
change over time
Productivity
Productive Work Content • A given task performed by a worker can be
considered to consist of – Basic productive work content
• Theoretical minimum amount of work required to accomplish the task
– Excess nonproductive activities• Extra physical and mental actions of worker• Do not add value to the task• Do not facilitate the productive work content• Take time
Productivity
• Excess Nonproductive Activities can be classified into three categories:– Excess activities due to poor design of product
or service– Excess activities caused by inefficient
methods, poor workplace layout, and interruptions
– Excessive activities cause by the human factor
Allocation of Total Task Time
Productivity
Work Systems
1. Manual work system– Worker performing one or more tasks without
the aid of powered tools2. Worker-machine system– Human worker operates powered equipment
3. Automated work system– Process performed without the direct
participation of a human worker
Manual Work Systems • Human body accomplishing some physical task
without an external source of power– With or without hand tools
• When hand tools are used, the power to operate them is derived from the strength and stamina of a human worker
– Other human faculties are required, such as hand-eye coordination and mental effort
Work Systems
Manual Work Systems
Work Systems
Work Systems
Pure Manual Work • Material handler moving cartons in a warehouse• Assembly worker snap-fitting two parts together
Manual Work with Hand Tools • Material handling worker using a dolly to move
furniture• Assembly worker using screwdriver
Work Systems
Worker-Machine Systems • Worker operating a piece of powered equipment• Examples:– Machinist operating a milling machine– Construction worker operating a backhoe– Truck driver driving an 18-wheeler– Worker crew operating a rolling mill– Clerical worker entering data into a PC
Worker-Machine Systems
Work Systems
Work Systems
Automated Work Systems • Automation is the technology by which a
process or procedure is accomplished without human assistance– Implemented using a program of instructions
combined with a control system that executes the instructions
– Power is required to drive the process and operate the control system
Automated Work System
Work Systems
METHODS DESIGN
Methods Design
• Motion study - analysis of the basic hand, arm, and body movements of workers as they perform work
• Work design - design of the methods and motions used to perform a task
• Includes:– Workplace layout and environment– Tooling and equipment used in the task
MethodsDesign Develop System
Standardize
Time Standards
Training
MOTION STUDY
WHAT IS MOTION AND TIME STUDY?
• Motion Study is designed to determine the best way to complete a repetitive job
Motion Study
Basic Motion Elements • Therbligs – 17 basic motion elements– Basic building blocks of virtually all manual work
performed at a single location– With modification, used today in several work
measurement systems
Motion Study
17 Therbligs 1. Transport empty (TE) – reach for an object2. Grasp (G) – grasp an object3. Transport loaded (TL) – move an object with hand
and arm4. Hold (H) – hold an object5. Release load (RL) – release control of an object6. Use (U) – manipulate a tool
Motion Study
7. Pre-position (PP) – position object for next operation
8. Position (P) – position object in defined location9. Assemble (A) – join two parts10. Disassemble (DA) – separate multiple parts that
were previously joined11. Search (Sh) – attempt to find an object using eyes or
hand
Motion Study
12. Select (St) – choose among several objects in a group
13. Plan (Pn) – decide on an action14. Inspect (I) – determine quality of object15. Unavoidable delay (UD) – waiting due to
factors beyond worker control16. Avoidable delay (AD) – worker waiting17. Rest (R) – resting to overcome fatigue
Classification of TherbligsEffective therbligs:• Transport empty• Grasp• Transport loaded• Release load• Use• Assemble• Disassemble• Inspect• Rest
Ineffective therbligs:• Hold• Pre-position• Position• Search• Select• Plan• Unavoidable delay• Avoidable delay
Motion Study
Micromotion Analysis • Objectives:– Eliminate ineffective therbligs if possible– Avoid holding objects with hand – Use workholder– Combine therbligs – Perform right-hand and left-hand
motions simultaneously– Simplify overall method– Reduce time for a motion, e.g., shorten distance
Motion Study
Example: A repetitive Manual Task
• Current method: An assembly worker performs a repetitive task consisting of inserting 8 pegs into 8 holes in a board. A sightly interference fit is involved in each insertion. The worker holds the board in one hand and picks up the pegs from a tray with other hand and inserts them into the holes, one peg at a time.
• Current method and current layout:
Example: A repetitive Manual Task
• Improved method and improved layout:– Use a work-holding device to hold and position the board while
the worker uses both hands simultaneously to insert pegs.– Instead of picking one peg at a time, each hand will grab four
pegs to minimize the number of times the worker’s hands must reach the trays.
Example A repetitive Manual Task
Motion Study
Principles of Motion Economy • Developed over many years of practical experience in
work design• Guidelines to help determine – Work method– Workplace layout– Tools, and equipment
• Objective: to maximize efficiency and minimize worker fatigue
Work Methods Design
To select preferred work method:1. Eliminate all unnecessary work2. Combine operations or elements3. Change the sequence of operations4. Simplify the necessary operations
Summary
• History of Motion and Time Study• Defining Work Systems and Productivity• Methods Design • Motion Study• Work Methods Design
References
• Groover, Mikell P., Work Systems: The Methods, Measurement & Management of Work, 2007, Prentice Hall
• Barnes, Ralph M., Motion and Time Study: Design and Measurement of Work, 1990, John Wiley & Sons Inc.
Improving Productivity
