Lean Quiz - Dr. Black's Notes

Question 1

What does TPS try to minimize and why?

Answer 1

• people
• inventory
• they don’t depreciate in cost

Question 2

TPS - Ohno - what did he do?

Answer 2

• reconstructed Job Shop (Mass Production) into manufacturing cells (Lean Production)
• turned final assembly into mixed model

Question 3

4 horsemen of lean manufacturing

Answer 3

1. Cost
2. quality
3. lead time
4. flexibility

Question 4

Flexibility (one of 4 horsemen of lean manufacturing)

Answer 4

• the capability of a manufacturing system to respond quickly to changes
• volume flex - changes in customer demand
• product flex - changes in product design
• lead time flex - ability to respond to customer orders

Question 5

Lean Production

Answer 5

• a system design composed of linked cells which can identify and eliminate waste (non-value added activities) to produce perfect goods at demand (pulls) of customers
• want to reduce TPT - to do so, identify and eliminate largest time traps using design rules for lean eng.

Question 6

Manufacturing System

Answer 6

• a complex arrangement of physical elements characterized by measurable parameters

Question 7

Flow Shop

Answer 7

• developed/used by Ford

- processes all lined up - sequenced

Question 8

Job shop

Answer 8

processes collected in departments

Question 9

Project Shop - fixed position layout

Answer 9

thing being manufactured there is so big that it cant be moved around the shop — civil engineers

Question 10

Continuous Process Layout

Answer 10

for oils, gases, etc. —- Chemical engineers

Question 11

Little’s Law

Answer 11

WIP = TPT X PR

Question 12

Takt Time

Answer 12

TT = 1 / PR

Question 13

Manufacturing System:

• how to control system
• rules

Answer 13

1. boundaries/ constraints of system must be defined
2. systems behavior in terms of its response to disturbances from environment must be predictable in terms of its measurable parameters
   - rules- laws used to describe how system works and generally require a “theory” which uses equations to describe behavior of systems and its boundaries in terms of input parameters - NO THEORY = NO VIABLE MODEL

Question 14

History of Factory Designs

Answer 14

• no factories early on - needed factories b/c materials made so strong that man power cant cut - need machines
• 1st is job shop
  2nd is flow shop (moving assembly line)
  3rd is TPS

Question 15

Economy of what? for each factory

Answer 15

• job shop - economy of collected processes
• flow shop - economy of scale
• TPS - economy of scope

Question 16

What Ohno did for Toyota

Answer 16

• changed final assembly into mixed model final assembly line
  - flex. and leveling - smoothing of prod. - demand
  being smoothed
• conveyor driven lines converted to self-balancing sub assembly lines
• cellular manufacturing
• setup reduction / SMED
• integrated quality - 7 tools and 6 sigma

Question 17

Kanban

Answer 17

Inventory and production control - JIT

Question 18

Kaizen

Answer 18

continuous improvement

Question 19

How does Final Assembly operate

Answer 19

• operated with Takt Time and operates on a MO CO MOO basis

Question 20

Poke Yokes

Answer 20

single machine tools used within built-in devices to check parts

Question 21

decouplers

Answer 21

device between machines designed to assist standing, walking workers producing parts in manufacturing cells
- SUSTAINS PART FLOW

Question 22

4 terms of lean engineering: Level

Answer 22

final assemble line (working with forecasts to make this line to level demand)

Question 23

4 terms of lean eng: Balance

Answer 23

what happens in the sub-assembly and manufacturing cells

Question 24

4 terms of lean eng: sequence

Answer 24

what happens to stuff when it goes from supply chain to final assembly

Question 25

4 terms of lean eng: synchronize

Answer 25

if something stops on final assembly, it stops also at sub-assembly. same with starting back up

Question 26

Takt Time Rule

Answer 26

-level and balance the man. system - make final assembly mixed model - cells produce daily demand - sequence and synchronize
TT = hours available in a day / DD
DD = (# you make/month) / (# days you work/month)
PR = production rate = 1 / TT
TT for final assembly = (Avail hrs/shift)/(available DD/shift)

Question 27

Self Balancing Sub Assembly Rule (OPF Rule)

Answer 27

• redesign subassembly lines into U-shaped SBSC’s that operate flexibly with OPF to match final assembly needs
• MO CO MOO (OPF with defect prevention

Question 28

Cell Design Rule (Lean Shop Rule)

Answer 28

MTij <= NCT where NCT = TT(1-allowance)

• the machine tools are single cycle automatics
• Cycle Time = Manual Time + Walking time
• dont add in machining times!
• every part that goes through cell goes through with same CT

Question 29

SMED Rule

Answer 29

• Shingo
• setup time reduction to where its equal to or less than CT
• SMED - less than 10 minutes
  1. determine whats happening now
  2. separate internal from external elements (external = you can do while machine is running)
  3. shift internal to external
  4. eliminate adjustments

Question 30

Kanban Rule

Answer 30

K = (DD X L + SS) / a
- DD is daily demand
- L is lead time
- SS is safety stock
- a is # of units in container
- K is # containers in Kanban Length
Ka = inventory in a single link
- for a link: Ka = L X DD = WIP
- for a system: WIP = TPT X PR
So sum of lead times for series of links = TPT for system
- all the inventory supplying the OPF is in these Kanban lengths - not 0 inventory  (its in the kanban lengths - its in the control of the ppl that use it)

Question 31

What did Ohno do with the cell design rule?

Answer 31

disconnected processing time from the schedule

Question 32

Toyota’s 5 R’s for reducing pollution

Answer 32

refine
reduce
reuse
recycle
retrieve energy