TW Chapter 5: Create Connected Process Flows

Question 1

What is the ideal in connected process flows?

Answer 1

One-piece flow, though it may not always be practical

Question 2

What is one-piece, or continuous flow?

Answer 2

A product that moves through the processing steps with minimal waiting time between, and the shortest distance traveled. This produces the highest efficiency.

Question 3

How are waste problems revealed?

Answer 3

By creation of flow, as this process forces the correction of problems.

Question 4

What effect does connected flow have on the entire enterprise?

Answer 4

It makes efficient addressing of problems a top priority, since the connected nature of the flow threatens to shut down the entire operation.

Question 5

What is the primary objective in continuous flow creation?

Answer 5

Waste elimination

Question 6

What is the production level in one-piece flow?

Answer 6

Each operation only builds what the next operation needs. No overproduction, for overproduction leads to the other types of waste.

Question 7

What are the strategies of connected process flow?

Answer 7

1. Continued elimination of waste
2. Force problems to surface
3. Make problems uncomfortable
4. Establish connected processes to create interdependency
5. Identify weak links in the flow and strengthen them

Question 8

What are the key criteria for achieving flow?

Answer 8

1. Ensure consistent capability
2. Consistent capability requires consistent application and availability of resources
3. Reliability of processes and equipment is imperative
4. Operation cycle times must be balanced to the takt time

Question 9

How is “flow” different from “pull?”

Answer 9

Flow: defined the state of material as it moves from process to process.
Pull: dictates when material is moved and who (the customer) determines that it is to be moved

Question 10

What are the three primary elements of “pull”?

Answer 10

1. Defined: a set agreement of volume, model mix, and sequence between supplier and customer
2. Dedicated: items from one supplier are bound to to one customer
3. Controlled: the defined agreement is maintained using simple, visually-apparent and physically-constraining control methods

Question 11

What is the kanban sign in pull?

Answer 11

An indication the customer makes to say “I am ready for more”

Question 12

What are the two reasons for a condition of deviation from flow?

Answer 12

1. The agreement is not visual, or not easily understood by everyone
2. There are additional problems the operators are compelled to work around

Question 13

What are the primary causes of deviation from flow by operators?

Answer 13

1. Imbalanced work cycle times (the person with extra time tends to deviate)
2. Intermittent work stoppages due to lack of parts, etc.
3. Intermittent work delays due to struggles with machines, or overly-complex tasks
4. Miscellaneous issues like “building ahead” to “buy time”, operators leaving the line, etc.

Question 14

What is buffer for, and how should it be used?

Answer 14

Buffer should be added to compensate for minor time variations between operators, but the quantity in the buffer must be defined as a standard (two or three pieces at most)

Question 15

What is there is not perfect balance in cycle times across all operations?

Answer 15

1. See if each operation can perform the task in less than the Takt time
2. Add a buffer if the average Takt time is low, but there is some variation between operators