Waste Elimination

Question 1

What is 5s?

Answer 1

tool for workplace organization and standardization

sort
straighten
shine
standardize
sustain

Question 2

What does each S mean?

Answer 2

sort - remove unneeded
straighten - arrange for ease of use
shine - cleanup campaign
standardize - maintain the system
sustain - make 5s the culture

Question 3

What is a pull system?

Answer 3

a system for managing scheduling and material flow so that overproduction and excess inventory are eliminated

Question 4

How does a pull system work?

Answer 4

• synchronizes production with customer demand
• replenishes product as it is consumed by a subsequent processing step
• seeks to produce only the exact products needed, in the exact quantity needed, in shortest lead time possible
• used when you want to reduce overproduction and inventory costs

Question 5

What are the characteristics of push systems?

Answer 5

• bases production on forecast or other mechanisms not directly linked to consumption
• creates products that are sent when made and stored where needed

Question 6

What are the characteristics of a pull system?

Answer 6

• limits production to only what has been consumed
• begins production with a pull signal
• products are stored where they are made and pulled when needed

Question 7

What are the consequences of a push system?

Answer 7

• risks mismatch between supply and consumption and, consequently a shortage or excess stock (excess is more common)
• requires less planning and guesswork to determine production plans

Question 8

What are the consequences of a pull system?

Answer 8

• results in match between supply and consumption
• material shortages are very visible
• delivers/produces in small quantities
• makes regular review of consumption levels (correct pull levels) essential

Question 9

What are the primary elements of a pull system?

Answer 9

1) Trigger
2) Flow
3) Upstream - ready process
4) Downstream - in-use process

Question 10

What are types of pull systems?

Answer 10

replenishment (supermarket)
sequential
mixed pull

Question 11

What is a replenishment (supermarket) pull system?

Answer 11

• each process has a “store” that holds a specific amount of product it produces
• consumption triggers replenishment
• system carries inventory for all products

Question 12

What is a sequential pull system?

Answer 12

• used if holding inventory isn’t feasible
• production is queued to control inventory
• kanaban cards signal production

Question 13

What is a mixed pull system?

Answer 13

• uses replenishment (supermarket) for high volume
• uses sequential for low volume

Question 14

What is kanban?

Answer 14

a system that ensures that material and information move into and out of a process in a timely manner

GOAL: materials do not arrive before they are needed

Question 15

When is kanban used?

Answer 15

• in pull systems
• to reduce overproduction
• reduce work-in-progress inventory costs

Question 16

What is standard work?

Answer 16

a method of documenting the current best practice for effectively and efficiently completing a process

Question 17

What does standard work documentation create?

Answer 17

• clear standards
• consistency
• efficiency
• reduces variation
• minimizes waste

Question 18

Standard work documents the ______________ best practice but it is intended to be _________________.

Answer 18

current
improved

Question 19

What are the benefits of standard work?

Answer 19

there can be no improvement where there are no standards

Question 20

What are the different time elements for measuring standard work?

Answer 20

cycle or process time = time for each step in process
lead time = total time including wait time
takt time = net time available to meet customer demand

Question 21

What is the takt time formula?

Answer 21

T = Ta/D

T = product assembly time required to meet demand
Ta = net time available to work
D = customer demand

Question 22

What is the formula for cycle time?

Answer 22

=net production time/number of units produced

Question 23

What is the lead time formula?

Answer 23

= order delivered - order received

Question 24

Standard Work In Progress (SWIP) tells us…

Answer 24

• if we are meeting SWIP target, process is flowing
• if # of products > SWIP, there is a bottleneck
• if # of products < SWIP, process is performing better than expected, insufficient products scheduled, or market demand has decreased

Question 25

What is a standard work chart?

Answer 25

a graphical view of the work cell, the path of the operator and the amount of standard WIP required to keep the process running smoothly

Question 26

What is the standard work combination table?

Answer 26

shows what the takt time is in comparison with the cycle time of the process

Question 27

What is the production capacity worksheet?

Answer 27

takes each step and breaks it down into manual time and automated time to define the total time per unit helps identify bottlenecks

Question 28

What is the standardized work chart?

Answer 28

a consolidated document that addresses: - takt time - work sequence - standard work in process (SWIP)

Question 29

What is poka-yoke?

Answer 29

mistake proofing a means of preventing errors from occurring through the use of physical, procedural, visual, or other forms of devices that prevent improper execution of a process step

Question 30

What is the difference between an error and a defect?

Answer 30

error = deviation from standard process defect = product does not meet specifications or customer expectations

Question 31

What is the relationship between errors and defects?

Answer 31

defects are caused by errors but not all errors will become defects

Question 32

What are sources of error? (7)

Answer 32

1) forgetting 2) dexterity limitations 3) fatigue 4) outside distractions 5) variation in component parts 6) ineffective maintenance 7) insufficient work instructions

Question 33

What are types of error? (9)

Answer 33

1) misunderstanding 2) misidentification 3) lack of training 4) willful 5) inadvertent (fatigue or distraction) 6) slowness (delay in judgment) 7) lack of standards 8) surprise (malfunction) 9) intentional (sabotage)

Question 34

What are defects caused by errors? (6)

Answer 34

- missed steps - set-up errors - missing parts - wrong part assembled - wrong part worked on - adjustment, measurement, or dimensional errors

Question 35

Remember: Everyone makes ____________. The goal is to design better _________, ______________, ____________, etc. to facilitate the ___________ or ____________ of mistakes and errors.

Answer 35

mistakes systems, procedures, environments reduction, elimination

Question 36

What are the characteristics of defects?

Answer 36

- attributes by nature - can't be measured; no "degree of goodness" - either works or doesn't; right or wrong - requires functional test or visual inspection

Question 37

What are the three components of a poka-yoke device?

Answer 37

- 100% inspection - rapid feedback - low cost and simple

Question 38

What are the two types of poka-yoke devices?

Answer 38

- prevention devices - detection devices

Question 39

What are the 5 principles of mistake proofing?

Answer 39

Elimination - remove defect causes Replacement - substitute a different process Facilitation - put something in place to facilitate the process of producing a good end result Detection - identify defect when it occurs Mitigation - reduce consequences of defect

Question 40

How do you standardize?

Answer 40

1) Approach - establish a standardized approach 2) Flow - what needs to be done regularly 3) Frequency - determine how often 4) Checklists - create standard 5s checklist 5) Responsible Parties - decide who is responsible for what 6) Combine - incorporate checklist into standard work instructions

Question 41

Standards should be... (7)

Answer 41

- concise - easy to understand - simple language (no technical jargon) - as visual as possible - comprehensive - reviewed and updated - communicated throughout