Exam #2

Four Types of Processes

1) Projects 2) Job shop processes 3) Flow shop (Assembly Line) 4) A continuous(Not Discrete)

Modes of Transportation

1. Air Speed=major advantage Expensive & quick, good for carrying expensive & perishable items 2. Rail Efficient for handling large tonnage over long distances Very expensive 3. Motor (Road) MOST flexible, handle door-to-door delivery, stop anywhere 4. Water Oldest mode of transportation, can handle extremely large shipments; ranked between rail and motor in terms of fixed cost 5. Pipelines Handle ~70% of all crude and petroleum ton-mile movements Extremely high fixed cost, though low VC to operate Multimodal

Types of Goods

1. Made to Start: configurations of standard parts, subassemblies, or services that can be selected by customers from a limited set ex) Dell computers, Subway sandwiches 2. Made to Order: custom goods, one of a kind ex) weddings, custom jewelery 3. Example to Order: standard goods ex) shoes, online courses

Types of Layouts

1. Product Layout: arrangement based on the sequence of operations that are performed during the manufacturing of a good or delivery of a service A: shorter processing times, less material handling, lower labor skills D: breakdown at one workstation can cause the entire process to shut down ex) winemaking industry, automobile assembly lines 2. Process Layout: functional grouping of equipment or activities that do similar work A: lower investment in equipment D: high movement and transportation costs, more complicated planning and control systems, longer total processing time, higher in-process inventory time, higher worker-skill requirements. ex) legal offices, hospitals 3. Cellular Man. Layout: design is not according to the functional characteristics of equipment, but rather by self-contained groups of equipment (called cells), needed for producing a particular set (family) of goods/services; used to centralize people expertise and equipment capability 4. Fixed Position Layout: consolidates the resources needed to manufacture a good or deliver a service A: Work remains stationary, reducing movement. D: High level of planning and control required. ex) production of large items such as heavy machine tools, airplanes, buildings, locomotives

Types of Processes

1. Projects: large-scale, customized, consist of many smaller tasks/activities that must be coordinated to finish on time and within budget. ex) Legal defense preparation, custom software development 2. Job Shop Processes: organized around general-purpose equipment that are capable of customizing work for individual customers; involves significant setup and/or changeover time, batching, moderate volume, many different products, high work-force skills, and customized to customer's specs. ex) hospitals, commercial printing 3. Flow Shop Processes: organized around a fixed sequence of activities to produce a small variety of similar goods/services. ex) automobiles, appliances, insurance policies 4. Continuous Flow Processes: creates highly standardized goods in very high volumes; 24/7 continuous operation, automated ex) gasoline, toy, steel factories

Types of Inventories

1. Raw materials: component parts, subassemblies, and supplies are inputs to manufacturing and service-delivery processes. 2. Work-in-process (WIP) inventory consists of partially finished products in various stages of completion that are awaiting further processing. 3. Finished goods inventory is completed products ready for distribution or sale. 4. Maintenance, Repair, and Operating (MRO) supplies: items used in operations but do not become parts of the finished goods, such as lubricants and cleaning supplies -Difference between RM and MRO: you do NOT plan to sell MRO MRO helps facilitate RM into the Work in Process MRO does NOT become part of finished goods 5. Cycle inventory (order or lot size inventory) is inventory that results from purchasing or producing in larger lots than are needed for immediate consumption/sale. 6. Safety stock inventory is an additional amount of inventory that is kept over and above the average amount required to meet demand

What is the difference between a value stream and a process map ?

A value stream map separates the activities to value adding and non value adding activities.

3. Continuous flow processes are used to create custom goods and services. a. True b. False

ANSWER: False

18. __________are large-scale, customized initiatives that consist of many smaller tasks and activities that must be coordinated and completed to finish on time and within budget. a. Projects b. Flow shops c. Continuous flow processes d. Assembly line processes

ANSWER: a

In a cellular layout, the procedure of classifying parts with similar processing requirements into families is called _____. a. group technology b. traits analysis c. batch processing d. commonality identification

ANSWER: a

15. Which of the following is true of fixed-position layouts? a. The changeover requirements are low. b. The automation potential is moderate. c. The volume of product demand is high. d. The equipment utilization is high.

ANSWER: b

28. One of the advantages of a product layout is that it: a. can easily accommodate a change in product design. b. has low work-in-process inventories. c. does not usually require highly specialized equipment. d. can easily accommodate new products.

ANSWER: b

Which of the following is a limitation of a process layout? a. It affects the entire system if any equipment in the layout fails. b. It has higher worker skill requirements. c. It has highly specialized equipment requirements. d. It generally requires a low investment for the production of machines.

ANSWER: b

23. Which of the following is a difference between flow shops and job shops? a. Unlike flow shops, job shops require little or no setup time. b. Unlike flow shops, job shops are organized around a fixed sequence of process steps. c. Unlike flow shops, job shops require frequent machine changeovers and delays. d. Unlike flow shops, job shops produce many large-volume goods and services.

ANSWER: c

30. Which of the following is true of a cellular layout? a. It remains stationary rather than moving work-in-process from one work center to another. b. Its workflow is not standardized. c. It is not designed according to the functional characteristics of equipment. d. Its quality problems are not addressed timely.

ANSWER: c

15. _____ are organized around particular types of general-purpose equipment that are flexible and capable of customizing work for individual customers. a. Assembly line processes b. Flow shop processes c. Continuous flow processes d. Job shop processes

ANSWER: d

27. Which of the following is true of flow shop processes? a. They produce low volumes of custom goods and services. b. They are large-scale, customized initiatives with wide variations in tasks. c. They have high setup or changeover time. d. They are organized around a fixed sequence of activities and process steps.

ANSWER: d

31. Which of the following types of facility layouts is best suited for a heavy machine tools factory? a. A product layout b. A process layout c. A cellular layout d. A fixed-position layout

ANSWER: d

Quantity Discount / Price-Break Model

Relaxed constant price assumption, 2 step procedure diff. between EOB and this model: -Quantity Discount model allows for quantity discounts, bigger order size = cheaper price

Economic Manufacturing Quality/Production Order Quantity Model

Relaxes the instantaneous replenishment assumption by allowing usage during production or partial delivery, appropriate for a manufacturing environment with simultaneous manufacture and consumption Inventory builds up gradually during the production period rather than at once as in the EOQ model Production rate (P) must be larger than consumption or demand rate (D), otherwise, orders cannot be filled

Product Process Matrix

View in one note

Projects

are large-scale, customized initiatives that consist of many smaller tasks and activities that must be coordinated and completed to finish on time and within budget. Characteristics: One-of-a-kind, large scale, complex, resources brought to site; wide variation in specs and tasks. Examples: Legal defense preparation, construction, custom jewelry, consulting, building airplane, custom software development, cruise ships.

Job shop processes

are organized around particular types of general-purpose equipment that are flexible and capable of customizing work for individual customers. Characteristics: Significant setup and/or changeover time, batching, low to moderate volume, many routes, many different products, high work-force skills, and customized to customer's specs. Examples: Many small manufacturing companies are set up as job shops, as are hospitals, legal services, commercial printing, and some restaurants.

moving average (MA) forecasting

average of the most recent "k" observations in a time series, as the value of "k" increases, the forecast reacts slowly to recent changes in the time series data. work best for: short planning horizons when there is no major trend, seasonal, or business cycle pattern

Statistical forecasting (Quantitative)

based on the assumption that the future will be an extrapolation of the past

In the context of data patterns in a time series, regular patterns in a data series that take place over long periods of time are called _____. a. orthographic patterns b. seasonal patterns c. cyclical patterns d. parallel patterns

c. cyclical patterns

ABC Inventory Analysis

categorizes SKUs into 3 groups according to total annual dollar usage; identifies best methods to control each category of inventory "A" items account for a large dollar value but relatively small percentage of total items. "B" items are between A and C. "C" items account for a small dollar value but a large percentage of total items.

14. The production of large goods such as ships is best accomplished using a _____. a. product layout b. process layout c. cellular layout d. fixed-position layout

d. fixed-position layout

Little's Law

explains the relationship among flow time (T), throughput (R) and work-in-process (WIP). Work-In-Process (WIP) = Throughput (R units/time) × Flow time (T time)

Assemble-to-order (Option)

goods and services are configurations of standard parts, subassemblies, or services that can be selected by customers from a limited set. Examples are Dell computers, Subway sandwiches, machine tools, and travel agent services.

Make-to-order (Custom)

goods and services are generally produced and delivered as one-of-a-kind or in small quantities and are designed to meet specific customers' specifications. Examples are ships, weddings, custom jewelry, estate plans, buildings, and most surgery.

Make-to-stock (Standard)

goods and services are made according to a fixed design, and the customer has no options from which to choose. Examples are appliances, shoes, sporting goods, credit cards, online Web-based courses, and bus service.

Cycle Time (CT)

interval between two successive outputs (time/unit)

The longest cycle is = to ?

is the sum of the of the task times

A continuous(Not Discrete)

low process creates highly standardized goods or services, usually around the clock in very high volumes. Characteristics: not made from discrete parts, very high volumes in a fixed processing sequence, high investment in system, 24/7 continuous operation, automated, dedicated to a small range of goods or services. Examples: chemical, gasoline, paint, steel factories, electronic funds transfer, credit card authorizations, and automated car wash. i.g. Oil Refinery

Economic Order Quantity (EOQ) Model

minimizes total cost, which is the sum of the inventory-holding (carrying) cost and the ordering (setup) cost; determines an optimal order quantity Assumptions: 1. Only a single item (SKU) is considered 2. Demand must be known & constant 3. Delivery time is known & constant 4. Replenishment is instantaneous 5. Price is constant (i.e., no quantity discounts) 6. Holding cost is known & constant 7. Ordering cost is known & constant 8. Stockouts are not allowed

Flow-blocking

occurs when a work center completes a unit but cannot release it because the in-process storage at the next stage is full. The worker must remain idle until storage space becomes available.

Lack-of-work delay

occurs whenever one stage completes work and no units from the previous stage are awaiting processing.

Throughput Time

output rate of a process (units/time)

Flow shop (Assembly Line)

processes are organized around a fixed sequence of activities and process steps, such as an assembly line, to produce a limited variety of similar goods or services. Characteristics: Little or no setup time, dedicated to small range of goods that are similar, similar sequence of process steps, moderate to high volume. Many option-oriented and standard goods are produced in flow-shop settings. Examples: automobiles, appliances, insurance policies, checking account statements, cafeterias, and hospital laboratory work.

Judgmental forecasting (Qualitative)

relies upon opinions and expertise of people in developing forecasts. When no historical data is available, only judgmental forecasting is possible. Pros: greater accuracy, canincorporate unusual or 1-time events,

Time Series

set of observations measured at successive points in time or over successive periods of time Characteristics: 1. Trend 2. Seasonal patterns: characterized by repeatable periods of ups and downs over short periods of time, usually within a year. 3. Cyclical patterns: regular patterns in a data series that take place over long periods of time, usually more than a year 4. Random variation (or noise): unexplained deviation of a time series from a predictable pattern, such as a trend, seasonal, or cyclical pattern. Because of these random variations, forecasts are never 100% accurate. 5. Irregular variation is a one-time variation that is explainable. For example, a hurricane can cause a surge in demand for building materials, food, and water.

Theory of Constraints

set of principles that focuses on increasing total process throughput by maximizing the utilization of all bottleneck work activities and workstations.

Assembly Line Balancing

technique to group tasks among workstations so that each workstation has (ideally) the same amount of work to balance an assembly line, one must know: 1. the set of tasks to be performed and the time required to perform each task 2. the precedence relations among the tasks 3. the desired output rate or demand forecast for the assembly line

The shortest cycle is = to ?

the largest task time.

Single Exponential Smoothing (SES) forecasting

uses a weighted average of past time-series values to forecast the value of the time series in the next period; forecast "smoothes out" the irregular fluctuations in the time series

Flow-blocking delay

when a work center completes a unit but cannot release it because the in-process storage at the next stage is full; the worker must remain idle until storage space becomes available.

Lack of work delay

whenever one stage completes work and no units from the previous stage are awaiting processing