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Chapter 14 - JIT and Lean Operations
CHAPTER 14
JIT AND LEAN OPERATIONS
Teaching Notes
JIT and Lean operations seem to be two of the most popular subjects for students. Some are a bit skeptical
at first, but most are fascinated by these Japanese approaches to repetitive production.
It has been said by some Japanese that JIT/Lean has its roots in Henry Ford’s assembly line. In fact, some
interesting parallels and comparisons can be made between JIT/Lean systems and production lines.
Perhaps the most challenging aspect of presenting JIT/Lean is where to start; i.e., which elements to
present first, and then, in which order to present the remaining elements.
It is important that students understand the difference between “romantic JIT/Lean” and “pragmatic
JIT/Lean” because many times students can fall into the same trap into which senior management has
fallen. Students may also see JIT/Lean as a quick fix to many problems without realizing that there are no
quick and easy solutions to these problems. It needs to be stressed to the students that it may take years to
perfect a JIT/Lean system by implementing various techniques related to machine changeovers, layout
design, product simplification, quality training, and preventive maintenance.
Answers to Discussion and Review Questions
1. The elements on which lean systems differ from traditional production systems are:
a. Inventory: Lean systems use minimal inventory necessary to operate while traditional
production systems use much inventory to offset forecast errors and late deliveries.
b. Deliveries: Lean systems use many, small deliveries while traditional production systems use
2. The ultimate goal of a lean system is a balanced system, i.e., one that achieves a smooth, rapid
flow of materials and/or work through the system, which in turn leads to competitive advantage
3. The JIT/Lean philosophy is embodied by five principles: (1) Identify customer values, (2) Focus
on processes that create value, (3) Eliminate waste to create flow, (4) Produce only according to
Education.
Chapter 14 - JIT and Lean Operations
14-4
Education.
supplier networks with a lean system becomes a high priority. Revising equipment and process
technology to process efficiently with high quality also will be an important consideration for
service firm due to decreased costs and increased customer service.
2. The change from a traditional operations system to a lean system encompasses the entire firm.
Therefore, if implemented correctly, the change to a lean system should affect the entire
3. Technology has had a profound effect on the implementation of lean systems. Improvement in
machine designs has resulted in better performance of machines, which in turn has resulted in
fewer defects, fewer machine breakdowns, and less inventory. The use of robots has enabled
companies to reduce setup times and setup cost, resulting in smaller lot sizes and lower inventory.
Use of the Internet and e-mail has increased the speed of communication between suppliers and
their customers.
Critical Thinking Exercises
1. Basic factors (characteristics) that must be in place to achieve a balanced lean system include:
2. Student answers will vary. Some possible answers include the following:
If top management promised workers than no workers would be terminated due to a lean
implementation and then turned around and fired workers, this action would violate the Virtue
Principle.
If top management of a firm forced its suppliers to implement Lean, but top management is
unwilling to implement Lean in its own facility, this action would violate the Rights Principle.
If a firm implemented Lean and dramatically increased the number of inbound shipments, thereby,
causing traffic jams in the surrounding neighborhood, this action would violate the Common Good
principle.
Chapter 14 - JIT and Lean Operations
Solutions
1. Given:
D = 80 pieces per hour
C = 45 pieces per container
T = 75 minutes
2. Given:
D = 100 parts per hour
C = 72 parts per container
3. Given:
D = 200 pounds per day
C = 20 pounds per container
T = 2 hours
14-6
4. Given:
Product
Daily
Quantity
A
21
B
12
C
3
D
15
Use the sequence A-B-C-D.
Determine the number of cycles per day and the production quantity per cycle:
Product
Daily
Quantity
Units per
Cycle
A
21
21/3 = 7
B
12
12/3 = 4
C
3
3/3 = 1
D
15
15/3 = 5
Pattern each cycle:
A(7), B(4), C(1), D(5).
