Learning Curve Analysis

Learning Objective

After this class the students should be able to:

Calculate the hours required to produce determinate product taking account the learning curve.

Time management

The expected time to deliver this module is 50 minutes.

30 minutes are reserved for team practices and

exercises and 20 minutes for lecture.

Learning Curve

Past experience indicates that

individuals learn by experience

(i.e., get better and better at the

job by carrying out the tasks

more and more).

Warm-up – 30 minutes

The student teams receive a bag containing pieces and are asked to assembly a same set for several times.

One team’s member is invited to chronometer the time that your team spend to assembly the set.

After the end, each team plots the results in a software (excel) and try to fit an exponential curve.

Learning curve

This phenomenon was first reported by T. P. Wright in 1936. But, the learning curve theory is based on assumptions such as those listed next Chase, R B., 1981

Learning curve assumptions

The time required to complete a specified task or unit of a product or item will be less each time the task is performed;

The unit time will reduce at a decreasing rate;

The decrease in time will follow a certain pattern, such as negative exponential distribution shape.

Learning Curve assumptions

The learning curve may vary one product to another and from one organization to another. The rate of learning depends on factors such as the quality of management and the potential of the process and products

Moreover, it may be said that any

change in personnel, process, or

product disrupts the learning curve.

Consequently, there is a need for the

utmost care in assuming that a learning

curve is continual and permanent.

Learning Curve Effects

NumberItem/Area

DescriptionTime Period

Cumulative Parameter

Learning Curve Slop Percentage

1 Steel making 1920 1955 Units Produced (UP)

Production Worker labor-hour per unit produced

79

2 Handheld 1975 1978 UP Average factory 74calculators selling price

3 Assembly of 1925 1957 UP Direct labor 80aircrafts hours per unit

4 Ford Motor 1910 1926 UP Price 86CompanyModel Tproduction

Some Information on Learning Curve Effects in U.S. Industrial Sector

The Table presents data on learning curve effects in the U.S. industrial sector . An 80% learning rate is descriptive of certain operations in such areas as ship construction, electronic data processing equipment, automatic machine production, and aircraft instruments and frame assemblies.

The learning curves are found to be quite useful in a variety of applications, including strategic evaluation of company and industry performance, internal labor forecasting, establishing costs and budgets, production planning, external purchasing, and subcontracting of items

The learning curve theory is based on a doubling of productivity. More specifically, when output or production doubles, the reduction in time per unit affects the learning curve rate. For example, an 80% learning rate means the second unit takes 80% of the time of the first unit, the fourth unit takes 80% of the second unit, the eighth unit takes 80% of the fourth unit, and so on.

Result

We may write

LHm = LH1m C

Where:

LHm is the labor hours required to produce unit

LH1 is the labor hours to produce unit one or the first unit.

C is the learning curve slope and is expressed by

log of the learning rate/(log2)

Discussion

Each team has to present an analyze of its results based on the theory presented in class

Exercise

Assume that the learning rate for a

certain operation is 75% and it took

90 hours to produce the first unit.

Calculate the hours required to

produce the fifth unit.

Solution

By substituting the given data value into C equation, we get

C = log 0.75/log 2 = 0.4150

Using the above value and the specified data in LHm = LH1m C yields

LH5 = 90(5)-0.4150

= 46.15 hours It will take 46.15 hours to produce the fifth unit.

Reference

“Engineering and Technology management

tools and applications” – Dhillon, B. S. Artec

House, Inc 2002.

Operation Analysis Using Excel – Weida,

2000, Duxbury.