BUAD 341 Lean Ops Exam 2

True/False: According to Lean Manufacturing, we should have ZERO inventory

FALSE

True/False: Lean Ops can only be applied to manufacturing

FALSE

Quality

The totality of features and characteristics ofa product or service that bears on its ability tosatisfy stated or implied needs

JIT

"Just in Time"

Determining the # of Kanbans needed:

- Each container represents the minimum production lot size (C) - # of containers (K) directly determines the amount of WIP in the system SO K = (Avg Demand During Lead Time + Safety Stock) / Size of the Container = (DL/S)/C

Additional principles of Total Quality Management (TQM):

- Employee empowerment - 85% of quality issuesare due to either processes or materials - Internal and external benchmarking - JIT, quality at the source and effective inspection

Supplemental 6: Statistical Process Control (SPC) Topics

- Employs control charts, with the purpose of distinguishing between common-cause and special-cause variation - Common- (random or natural) vs. special- (assignable)cause variation - X-bar & R charts, when population variance is unknown: (Ability to compute LCL & UCL for each chart type Table with A2, D3, & D4 adjustment factors will be provided) - Interpretation of control charts

The 5 S's

sort, straighten, shine (or sweeping), standardize, sustain (or self-discipline)

Ch. 6 - Managing Quality Topics

- How do we define & assess quality - Cost of Quality - Total Quality Management (TQM): (Major Elements, including Six Sigma; Key tools, including Check Sheets, Scatter Diagrams, Cause-and-Effect Diagrams, Pareto Charts, and SPC)

Just-in-Time (JIT) systems make demands on layouts, including the need for:

- Increased flexibility - Distance reduction - Reduced space and inventory - Cross-trained, flexible employees

Ch. 16 Lean Principles Topics:

- Sources of waste - Classification of lean principles (Characteristics, How does each contribute to eliminating waste?, What particular sources of waste is each principle addressing) - Little's Law - Determining the number of Kanban cards/containers

Key TQM Diagrams

1. Check Sheet 2. Scatter Diagram (identifies correlations btw 2 variables) 3. Cause-and-Effect Diagram (fishbone/arrow one) 4. Pareto Chart (IDs & plots problems in descending frequency) 5. Statistical Process Control (Control charts based on stats- improvement through elimination of special causes and gradual reduction of common causes) **Note: special cause: non-random, common cause: random

Understanding the SERVQUAL model (image on slide 4 of Managing Quality.ppt)

1. Expected Service < Perceived Service = Quality surprise :D 2. Expected Service = Perceived Service = Satisfactory Q :) 3. Expected Service > Perceived Service = Unacceptable Q :/

One-Piece Flow

A single product moving through all stages of production one at a time. Requires constant effort to reduce setup times.

Dimensions of Service Quality

1. Tangibles - the appearance of physical facilities, equipment, personnel, and communication materials(supporting facilities & facilitating goods) 2. Reliability - the ability to perform the promised service dependably and accurately (explicit service) 3. Responsiveness - a willingness to help customers and to provide prompt service (implicit service) 4. Assurance - knowledge and courtesy of employees& ability to convey trust and confidence (implicit) 5. Empathy - the provision of caring, individualized attention to customers (implicit)

The 7 Forms of Waste (TIMWOOD)

1. Transportation 2. Inventory 3. Motion 4. Waiting 5. Overproduction 6. Overprocessing 7. Defects & a secret 8th one: this class.

X-Bar and R Chart Formulas:

1. X-bar: The average of each subgroup X-bar = Σx / n where Σx represents the sum of individual measurements within a subgroup and n is the subgroup size. 2. Range (R): The difference between the highest and lowest values in each subgroup R = max(x) - min(x) 3. R-bar: The average range across all subgroups R-bar = ΣR / m 4. Control Limits: X-bar Chart: - Upper Control Limit- UCLx = CL + (A2 × R-bar) - Lower Control Limit- LCLx = CL - (A2 × R-bar) 5. Control Limits: R Chart: - Upper Control Limit- UCLr = D4 × R-bar - Lower Control Limit- LCLr = D3 × R-bar Note: A2, D3, and D4 are control chart constants that depend on the subgroup size (n) <- refer to the control chart given in the slides. (WRITE ON SHEET)

People are waiting in line at the theater. The cashier serves 1 customer/minute. The line is 10 people long (excluding you). How long are you going to wait in line?

10 minutes Explanation: THr = 1 customer per minute WIP = 10 people THt = What we're looking for. WIP = THt * THr SO... THt = WIP/THr. THt = 10 people / 1 cust. per minute Throughput time: 10 Minutes.

If it takes 7 machines 7 minutes to make 7 widgets, how long would it take 100 machines to make 100 widgets?

100. Each machine can make ONE widget in 7 minutes. So if each of the 100 machines makes one widget, then it would only take 7 minutes to get 100 widgets.

How many kanbans do you need for the following connector? Daily demand: 1,600 connectors Lead time: 4 days Safety stock: 0.50 day Kanban size: 500 connectors Note: This is a level production system so daily production rate = daily demand rate ^ why does that note matter? I have no idea, but it seemed important, so there ya go.

14.4 kanbans STEPS: 1. Demand during lead time = 4 days * daily demand of 1,600 = 6,400 connectors 2. Safety stock = 0.50 day of production * daily demand of 1,600 = 800 connectors 3. Lot size = Demand during lead time + safety stock = 1,600 +800 = 7,200 connectors 4. Number of kanbans = (Demand during lead time + Safety stock) / Size of container = 7,200/500 ***** = 14.4 kanbans *****

The following data has been provided. How many kanbans are needed? Daily demand: 275 units Production lead time: 3 days Safety stock: 1.50 days Kanban size: 50 units

24.75 kanbans STEPS: 1. Demand during lead time = 3 days * 275 daily demand = 825 units 2. Safety stock = 1.50 days of prod. * 275 daily demand = 412.5 units 3. Lot size = demand during LT + safety stock = 825 +412.5 = 1237.5 units 4. # of kanbans =(DL/S)/Container size = 1237.5/50 = ****24.75 kanbans****

Mixed-Model Assembly

A production system that is capable of producing multiple variations of a product on the same assembly line. The goal is to achieve flexibility and efficiency in meeting customer demand for different product configurations while minimizing waste and optimizing resource utilization.

Pull System

A concept that results in material being produced only when requested and moved to where it is needed just as it is needed

Kanban

A manual system that signals the need for parts or materials; A Japanese word meaning "card" or "visible record" that refers to cards used to control the flow of production through a factory. A ticket-based JIT system that indicates when to reorder inventory.

Control Charts

A variety of charts can be constructed, dependingon the metric that is measured

A company has decided to switch from a PUSH system to a PULL system. They are a large repetitive manufacturer of bicycles. Which one of the following is most likely to occur? A. Decrease in WIP inventory levels will reduce the space requirement B. Workers at any given process will produce units before they are needed C. The cycle time will increase, resulting in higher inventory levels D. The space required will increase due to the increase in the # of units that require re-work.

A. Decrease in WIP inventory levels will reduce the space requirement NOT B: Making inventory in advance would be for a push system NOT C: The throughput rate (THr) does not change between a Push or Pull system. NOT D: Nothing in the Q hints to this.

Six Sigma is:

An element of Total Quality Management. A comprehensive program focused on total customer satisfaction, including a Strong discipline - DMAIC model

Which of the following is an illustration of employee empowerment? A. UPS drivers are trained to perform several motions smoothly and efficiently. B. "No one knows the job better than those who do it." C. Unionization of the work place brings better morale and therefore better quality. D. All of the above E. None of the above

B. "No one knows the job better than those who do it."

Which of the following is NOT an attribute of lean​ operations? A. minimizing space requirements by reducing the distance a part travels B. pushing responsibility to the highest level possible through centralized decision making Your answer is correct. C. eliminating almost all inventory through​ just-in-time techniques D. building worker flexibility through​ cross-training and reducing job classifications E. educating suppliers to accept responsibility for helping meet customer needs

B. pushing responsibility to the highest level possible through centralized decision making

Which of the following is NOT a lean scheduling tactic? A. Use kanbans B. Make level schedules C. Produce in large lots to minimize setup costs D. Freeze part of the schedule

C. Produce in large lots to minimize setup costs

Group technology

Combining parts or products with similar characteristics into families and setting machines aside for their production

There are many requirements for the successful implementation of the lean system of production. Which one of the following is NOT such a requirement: A. Low machine failure and low defects. B. Uniform assembly schedule. C. Short setup time D. Substantial natural resources.

D. Substantial natural resources.

Companies using lean systems generally have: A. Suppliers who are low-cost producers B. Suppliers that are willing to accept short-term contracts C. Many suppliers to ensure that material shortages never occur D. Suppliers that are located nearby to decrease delivery lead time

D. Suppliers that are located nearby to decrease delivery lead time

DMAIC model

Define - project's purpose, scope, and outputs subject to the customer's definition of quality Measure - the target process and collect data Analyze - the data ensuring repeatability and reproducibility Improve - by modifying or redesigning existing processes and procedures Control - the new process to make sure performance levels are maintained

Special Process Control (SPS) and common causes on a bell curve:

If only common causes of variation are present, the output of a process forms a distribution that is stable over time and is predictable

Special Process Control (SPS) and special causes on a bell curve:

If special causes are present, the process output is not stable over time and is not predictable

Lean systems use the standardization of components because standardization:

Increases repeatability

if interested in tracking multipledimensions simultaneously, use:

Multivariate charts

Throughput (THt) or Turn Around Time (TAT)

Process Performance Metric. Total time required to complete one unit of a product or service. Shorter THt -> Less Cost -> More Profit

Push System

Produces goods in advance of customer demand using a forecast of sales and moves them through supply chain to points of sale where they are stored as finished goods inventory.

Which system tends to have a lower throughput time? Pull or Push?

Pull System. Remember: THt = WIP/THr. The throughput rate (THr) will stay the same no matter which system you use. We know that a Pull System has **less** WIP than a Push System, so a smaller number divided by the THr will give us a lower throughput time (THt)

Which system tends to have a higher level of WIP (Work in Process)? Pull or Push?

Push System. Remember: a push system is already producing materials in anticipation of demand, so there will be more products in the production line, therefore increasing WIP!

Total Quality Management

Refers to a consistent and comprehensive focus on quality that encompasses the entire organization Quality is defined by identifying and meeting customer expectations Management is directly responsible for quality improvement Requires a **continuous effort** to analyze and improve organizational processes

Lean Production

Set of integrated activities designed to achieve high volume production while minimizing waste in the production process (muda). Sometimes called TPS, "JIT", or "Big JIT"

Big JIT

Sounds like a mess you got yourself into. "Dang, I got myself into some Big JIT..." Okay, now to actual terms...

Who is Taiichi Ohno?

The father of Toyota Production System (TPS) and lean production principles. Combined Ford's assembly line idea and supermarket operations. Goal: reduce waste and only produce what is needed.

Little's Law

WIP = THt * THr WIP: represents amt of work in process THt: throughput time THr: throughput rate (units/time)

Charts to use for continuous variables (length, weight, thickness, etc.)

X-Bar and R charts

X-Bar and R charts MUST:

be used together, as both the mean and the variability are critical metrics that need to be tracked to assess process performance

Charts to use for attribute variables (defective, non-defective)

c charts - if dealing with counts of defects p charts - if interested in the proportion of defects u charts - if interested in the number of defects per unit of output

X-Bar charts

track changes in central tendency(i.e., the mean) of a process

R charts

track changes in process variability