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 ```