Lean Operations

Question 1

What is the core philosophy of TPS?

Answer 1

Eliminate waste

Question 2

What are the goals of TPS?

Answer 2

-Reduce cost
-Improve quality
-Improve timeliness

Question 3

What are the core principles of TPS?

Answer 3

-Just-In-Time
-Jidoka
-Heijunka
-Andon
-Poka-yoke
-Kaizen

Question 4

What is JIT and what is its main objective?

Answer 4

-Make and deliver products according to exactly what is needed
-This is to minimise WIP inventory

Question 5

What is the benefit of reducing WIP inventory?

Answer 5

It increases problem visibility

Question 6

What are the 3 JIT practices?

Answer 6

-Continuous Flow
-Takt Time
-Pull System

Question 7

What are the benefits of continuous flow?

Answer 7

-Reduces WIP inventory
-Reduces waiting time

Question 8

-What are the requirements to implement a continuous flow process?

Answer 8

-Reduce setup time
-Create a layout that reduces transport

Question 9

What is Takt Time?

Answer 9

-Produce at a rate in line with demand
-Takt time= Total production time/ customer demand

Question 10

What are the benefits of Takt Time?

Answer 10

Reduces finished goods inventory

Question 11

What is a push system?

Answer 11

Materials are pushed downstream in a supply chain

Question 12

What is a pull system?

Answer 12

-Materials are pulled upstream from downstream workstation
-This is triggered by a downstream demand signal

Question 13

What are the benefits of a pull system?

Answer 13

-Reduces WIP inventory

Question 14

What is Heijunka?

Answer 14

-Production of mixed products is done in a sequence of small batches

Question 15

What are the benefits of Heijunka?

Answer 15

-Smoothed production schedule
-Reduces inventory
-Synchronisation with customer demand
-Smoother demand on the upstream processes and suppliers
-Balances the use of labour and machines

Question 16

What are the requirements of Heijunka?

Answer 16

-Short setup and changeover times

Question 17

What is Jidoka?

Answer 17

Quality control

Question 18

What are the Jidoka practices?

Answer 18

-Quality at source
-Human-machine separation

Question 19

What is quality at source?

Answer 19

-Inspect quality during the production process rather than at the end
-Never pass on defective units to the next process
-This minimises rework

Question 20

What is Andon?

Answer 20

A system that displays and alerts operators and managers of real time status and problems of a process or product quality

Question 21

What are the benefits and drawbacks of Andon?

Answer 21

-Lower risk of snowballing waste due to defects
-Cost depends on the duration of the line stop
-Therefore processes should be in place to ensure the the stop time is minimised

Question 22

What is Poka-Yoke?

Answer 22

-Mistake proofing
-Components are designed in such a way such that it is impossible to assemble them incorrectly

Question 23

What is human-machine separation?

Answer 23

-Work is executed with different timelines for the people and machines involved
-If the machines are fully automated, this means the people can do other tasks while the machines work

Question 24

What is Kaizen?

Answer 24

Engage every employee to continuously improve the process

Question 25

What are the 7 sources of waste?

Answer 25

-Overproduction
-Waiting
-Transport
-Overprocessing
-Inventory
-Rework
-Motion

Question 26

How does reducing inventory expose problems?

Answer 26

-It exposes defects quickly and allows the determination of the root cause of the problem
-Causes short term losses in throughput