ops mgmt test 3
job shop
usually operates on a relatively small scale. It is used when a low volume of high variety goods or services will be needed (high variety, low or very low volume)
time fences
series of time intervals during which order changes are allowed or restricted; the nearest fence is the most restrictive ti change, the furthest is least restrictive to change
Which of the following would probably not involve the use of PERT/CPM?
processing paper at a paper mill
The Styro film produced by John Deere...
showed that major improvements in an operating/production system must be made so that the low inventory levels and small batch sizes recommended for a JIT system can be successful
The type of layout features departments or other functional groupings in which similar activities are performed is called...
process layout
just in case inventory
used to cover up the problems so that their effects are not directly felt
batch
used when a moderate volume of goods or services is desired, it can handle a moderate variety in products or services (moderate variety, Moderate volume)
In the lean/Just-in-time philosophy, setups taken to mistake-proof a process are called...
poka yoke
demand
process choice is ____ driven
technique of distributing time buffers...
1. Each operation is buffered of protected to a certain extent 2. the system has, in general, more buffer than any single operation 3. the amount of buffer (protection) available depends on the location of the disruption in the process. The further along in the process the disruption occurs, the less protection is available
Drawbacks of traditionally managed MRP include...
1. MRP ignores the existence of constraints 2. Resources are managed to maximize local efficiencies
3 limitations to assembly lines
1. assembly lines are of limited applicability 2. they require huge investments of both capital and labor 3. the throughput of assembly line processes is highly vulnerable to the disruptions that often occur
Invalid assumptions of the traditional approach
1. assumes that the carrying cost is comprised of only the dollar cost to actually carry the inventory. 2. does not make a distinction between the value of setup time at a bottleneck versus that of a non-bottleneck resource. 3. assumes there is only one kind of batch size to consider when, in fact, there are two distinct and very different types of batches
Time buffers are needed....
1. at the end of the process, before shipping 2. in front of the capacity constraint resources (CCRs)
Limitations of MRP II...
1. do not effectively protect against disruptions 2. do not differentiate between bottleneck and non-bottleneck resources 3. do not provide for a focused process of improvement
In lean/Just-in-time, the seven types of waste include all of the following...
1. inventory 2. overproduction 3. transportation 4. inefficient work methods
The rope in drum-buffer-rope...
1. is the methodology used to ensure the required synchronization in the operation without having to actively control each individual resource. 2. generates timely release of just the right materials into the system at just the right time
applying the concept of physical ropes for an assembly line
1. the finished goods being produced must be fairly standardized 2. the processes required to produce the finished goods must be such that there is a single-direction, in line flow of material from one work station to the next. 3. There must be a high level of demand for the product in order to warrant special manufacturing lines dedicated to the high-volume production of a standardized product
product process fixed position
3 basic type of layouts...
fixed programable flexible
3 types of automation...
1. logistical transactions- ordering, execution, and confirmation of materials transported from one location to another 2. balancing transactions- forecasting, production planning, production control, scheduling and order processing 3. quality transactions- determining and communication specifications and monitoring, recording, and follow up activities
3 types of reduced transaction processing?
1. standard parts 2. modular design 3. highly capable production system with quality built in 4. concurrent engineering
4 elements of product design for a lean production system?
1. workers as assets 2. cross train workers 3. continuous improvement 4. cost accounting 5. leadership/project management
5 important personal/organizational elements for lean systems?
1. identify customer values 2. Focus on processes that create value 3. eliminate waste to create flow 4. produce only according to customer demand 5. strive for perfection
5 principles of the lean system..
1. level loading 2. pull systems 3. visual systems 4. limited work in process 5. close vendor relationships 6. reduce transaction processing 7. preventive maintanence and housekeeping
7 manufacturing planning and control elements important for lean systems?
1. small lot sizes 2. setup time reduction 3. manufacturing cells 4. quality improvement 5. production flexibility 6. a balanced system 7. a little inventory storage 8. failsafe methods
8 important aspects of process design for lean production systems?
CH 6 STEVENSON
CH 6 STEVENSON
Ch 14 STEVENSON
Ch 14 STEVENSON
Drum
Considers the constraints in the system and sets the pace for the entire system
lot sizing
For independent demand items, managers often use economic order sizes and economic production quantities. For dependent demand systems, however, a much wider variety of plans is used to determine lot sizes, mainly cus no single plan has a clear advantage over the others
Henry Ford
He applied the basic concept of physical ropes and developed his assembly line production facilitates. He connected his assembly line production resources with a system of conveyor belts.
KEY POINTS CH 12 1.The usage of components and production of assembled items depends on how many of each component are needed per item, and how many items are to be produced. Hints the term dependent demand. 2. MRP is a tool used for dependent demand components, to assist in making the 2 basic decisions in inventory management: how much of each component to order and when to order it 3. MRP II is an enhancement of MRP that gives management the ability to relate financial and other info to an MRP plan 4. ERP is a software based enterprise wide system that allows access to production, sales, accounting, warehouse, and supply chain info
KEY POINTS CH 12 1.The usage of components and production of assembled items depends on how many of each component are needed per item, and how many items are to be produced. Hints the term dependent demand. 2. MRP is a tool used for dependent demand components, to assist in making the 2 basic decisions in inventory management: how much of each component to order and when to order it 3. MRP II is an enhancement of MRP that gives management the ability to relate financial and other info to an MRP plan 4. ERP is a software based enterprise wide system that allows access to production, sales, accounting, warehouse, and supply chain info
individual whole
Kanbans control of WIP focuses on _____ work stations, while constant WIP focuses on the system as a ______
1. What is needed? 2. How much is needed? 3. When is it needed?
MRP is designed to answer what 3 questions?
1. a computer and the necessary software programs to handle computations and maintain records 2. accurate and up to date master schedules, bill of materials, and inventory records 3. integrity of file data
MRP requirements....
Buffer
Protects the system from the disruptions inherent in any process (slack that exists in the rope)
READ OVER it is critical for companies to figure out if their ways of doing business will fit within a standard erp package before the checks are signed and the implementation begins The move to erp is a project of breathtaking scope and the price tags on the front end are enough to make the most placid CFO a little twitchy ERP is very expensive; the total cost of ownership of erp is hundreds of thousands of $ to hundred of millions of $
READ OVER it is critical for companies to figure out if their ways of doing business will fit within a standard erp package before the checks are signed and the implementation begins The move to erp is a project of breathtaking scope and the price tags on the front end are enough to make the most placid CFO a little twitchy ERP is very expensive; the total cost of ownership of erp is hundreds of thousands of $ to hundred of millions of $
Synchronous Management Principle 5
Resources must be utilized, not simply activated
summary of ch. 8
Setting the drum provides a systematic approach to developing a master production schedule that is consistent with the constraints of the system. Time buffers are established to protect overall plant performance from the devastating effect of disruptions. The rope provides a simple and straightforward approach to controlling the production process. DBR system is totally consistent with the seven synchronous management principles.
Stevenson ch 12
Stevenson ch 12
Synchronous Management Principle 4
The level of utilization of a non-bottleneck resource is controlled by the constraints of the system
safety stock
Theoretically, inventory systems with dependent demand should not require safety stock below the end item level. This is one of the main advantages of an MRP approach. Supposedly, safety stock is not needed because the manager can project precise usage quantities once the master schedule has been established because demand is not variable.
1. job shop 2. batch 3. repetitive 4. continuous 5. project
What are the 5 basic process types?
1. a master schedule 2. a bill of materials file 3. an inventory records file
What is a MRP's systems 3 major sources of info?
stressed
flexibility is ______ only if needed decision makers choice flexible systems for 2 reasons- demand variety or uncertainty exists about demand
lean operation
a flexible system that uses minimal resources and produces high quality goods or services
assets
a fundamental tenet of the lean philosophy is that workers are ______
flexible manufacturing system(FMS)
a group of machines designed to handle intermittent processing requirements and produce a variety of similar products
just in time (JIT)
a highly coordinated processing system in which goods move through the system, and services are performed, just as they are needed
bill of materials (BOM)
a listing of all the raw materials, parts, sub assemblies, and assemblies needed to produce one unit of a product
kanban system
a manual system that signals the need for parts or materials
distribution resource planning (DRP)
a method used for planning orders in a supply chain
material requirements planning (MRP)
a methodology that translates master schedule requirements for end items into time based requirements for sub assemblies components and raw materials
Synchronous Management Principle 7
a process batch may be variable both along its route and over time
In Synchronous Management, Vol. 1, material flow in a manufacturing environment is compared to...
a river
computer integrated manufacturing (CIM)
a system for linking a broad range of manufacturing activities through an integrating computer system the overall goal of using this is to link various parts of an organization to achieve rapid response to customer orders and or product changes, to allow rapid production, to reduce indirect labor costs.
single minute exchange of die (SMED)
a system for reducing changeover time
product structure tree
a visual depiction of the requirements in a bill of materials, where all components are listed by levels
value stream mapping
a visual tool to systematically examine the flow of materials and info
activity based costing
allocation of overhead to specific jobs based on their percentage of activities
Traditional approach to batch-sizing
annual setup cost and the total carrying cost are the two main factors. There is an inverse relationship between batch size and setup cost
ERP
attempts to integrate all departments and functions across a company onto a single computer system that can serve all those different departments particular needs so that various departments can easily share info and communicate with each other
autonimation
automatic detection of defects during production
1. low levels of in process inventories, due to an exact matching of supply to demand 2. the ability to keep track of material requirements 3. the ability to evaluate capacity requirements generated by a given master schedule 4. a means of allocating production time 5. the ability to easily determine inventory usage by back flushing
benefits of mrp...
pressure
business organizations are facing increasing _______ to operate sustainable production processes
Kanban
card or other device that communicates demand for work or materials from the preceding station
CH 14 summary
ch 14 summary The goal of a lean system is achieve a balanced smooth flow of operations. The building blocks of a lean production system are product design, process design, personel and organization, and manufacturing, planning and control. Key benefits of lean systems are reduced inventory levels, high quality, flexibility, reduced lead times, increased productivity and equipment utilization, reduced amounts of scrap and rework, and reduced space requirements. The goal of JIT system is to achieve a continuous work flow using minimal resources, producing only what is needed when it is needed. Benefits of a JIT system is substantial reduction in both WIP and finished goods inventories, which leads to a substantial reduction in the amount of working capital devoted to inventories. JIT: repetitive production system in which processing and movement of materials and goods occur just as they are needed, usually in small batches Lean systems produce high quality goods or services using fewer resources than traditional operation systems Lean thinking helps business organizations become more productive, reduce costs, and be more market responsive Lean operations are designed to eliminate waste (value stream mapping), minimize inventory, maximize workflow(small batches with quick changeovers), make only what is needed (demand pool), empower work teams, do it right the first time, and continually improve. JIT is sometimes viewed as a system for repetitive production operations while MRP is considered a system for batch production MRP systems are complex, requiring extensive in detail shop floor controls JIT systems involve only minimal shop floor controls MRP relies on a computer based component scheduling system to trigger production and deliveries, whereas JIT relies on visual or audible signals to trigger production and deliveries
waste reduction continuous improvement use of teams work cells visual controls high quality minimal inventory output only to match demand quick changeovers small lot sizes lean culture
characteristics of lean systems...
Which of the following is an advantage of a product layout?
costs per unit are low due to the high volume of production
dependent demand
demand for items that are are sub assemblies or component parts to be used in the production of finished goods
load reports
department or work center reports that compare known and expected future capacity requirements with projected capacity availability
Which of the following is/are true?
dependent demand is demand for subassemblies or component parts to be used in the production of finished goods
enterprise application integration
erp is now about _____ ______ _______.
closed loop mrp
evaluate a proposed material plan relative to available capacity. (MRP II systems begin to include feedback loops and thats when they were referred to as closed loop mrp)
manufacturing resource planning II (MRP II)
expanded approach to production resource planning involving other areas of a firm in the planning process and enabling capacity requirements planning
project on hand
expected amount of inventory that will be on hand at the beginning of each time period
back flushing
exploding an end items BOM to determine the quantities of the components that were used to make the item
The process that involves the identification of items with similarities in either design characteristics or manufacturing characteristics for the purpose of grouping them into part families known as...
group technology
The JIT philosophy...
highly successful Japanese philosophy led by Toyota. has guided the development of systems designed to reduce inventory, scrap, rework, and the space and equipment required to handle inventory, while improving product quality and responsiveness to a an ever-changing market
ERP automates the tasks involved in performing a business process such as order fufillment
how can ERP improve a companies business performance?
1. the big bang- the most ambitious and difficult of approaches to erp implementation, companies cast off all their legacy systems at once and implement a single erp system across the entire company 2. Franchising strategy- this approach suits large or diverse companies that do not share many common processes across business units, independent erp systems are installed in each unit while linking common processes such as financial book keeping across the franchise 3. slam dunk- generally for smaller companies expecting to grow into erp, goal is to get erp up and running quickly and to ditch the fancy reengineering in favor of the erp systems canned processes
how do companies organize their erp projects? 3 of them and explain each
usually between 1-3 years (companies that install ERP do not have an easy time with it)
how long will an ERP project take?
Is DBR classified as a push or pull system?
includes characteristics of both. materials are pulled into the plant only as needed to support the constraint and shipping schedules. the non constraints must process all the materials and push these materials forward to the constraint and to shipping as fast as possible
inventory records
includes information on the status of each item by time period called time buckets
enterprise resource planning (ERP)
integration of financial, manufacturing, and human resources in a single database
MRP
is a planning and scheduling technique used for batch production of assembled items
U-shaped layout
is more compact and often requires half the length of a straight production line and it increases communication of workers thus facilitating teamwork; flexibility and work assignments is increased and the U-shaped minimizes material handling
project
is used for work that is non routine, a non repetitive set of activities directed toward a unique goal within a limited time frame
Which type of processing system is likely to see the most variety of output?
job shop
fixed position layout
layout in which product or project remains stationary, and workers, materials, and equipment are moved as needed
cellular production
layout in which work stations are grouped into a cell that can process items that have similar processing requirments
product layout
layout that uses standardized processing operations to achieve smooth, rapid, high volume flow
process layout
layouts that can handle various precessing requirements
cooperative
lean systems require a ______ spirit among workers, management, and vendors
product or service profiling
linking key product or service requirements to process capabilities
Drum-buffer-rope system
logistical system that incorporates the key strengths of assembly lines, MRP II systems, and JIT systems while overcoming the weaknesses
automation
machinery that has sensing and controlled devices that enable it to operate automatically
numerically controlled machines(N/C)
machines that perform operations by following mathematical processing instructions
housekeeping
maintaining a workplace that is clean and free of unnecessary materials
preventative maintenance
maintaining equipment in good operating condition and replacing parts that have a tendency to fail before they actually do fail
The MRP input stating which end items are to be produced, when they are needed, and in what quantities is called?
master schedule
Rope
mechanism for synchronizing all resources in the system to the drum (mechanism by which the pace of the entire troop is restricted
services manufacturing
mrp has applications in _____ as well as in ______.
intermittent processing
non repetitive processing
What happens when there is an improperly chosen batch size?
non-synchronized material flows, with the direct result being increased levels of inventory and operating expenses
scheduled reciepts
open orders scheduled to arrive from vendors or elsewhere in the pipeline
1. holding of safety stock 2. lot sizing choices 3. possible use of MRP for unfinished products
other aspects of MRP include...
secondary reports
performance control, planning, and exceptions 1. performance control reports- a valuation of system operation, including deviations from plans and cost information 2. planning reports- data useful for assessing future material requirements 3. exception reports- data on any major discrepancies encountered
planned order releases
planned amount to order in each time period; planned order receipts offset by lead time
product layouts are most conductive to repetitive processing, process layouts are used for intermittent processing, and fixed position layouts are used when projects require layouts
product layouts are most conductive to repetitive processing, process layouts are used for intermittent processing, and fixed position layouts are used when projects require layouts
primary reports
production and inventory planning and control 1. planned orders- a schedule indicating the amount and timing of future orders 2. order releases- authorizing the execution of planned orders 3. changes- revisions of due dates or order quantities, or cancelations of orders
The main output of MRP is...
purchase and production schedules
planned order reciepts
quantity expected to be received by the beginning of the period in which it is shown
JIT system
reducing the inventory has succeeded in quickly identifying a problem, but that problem has temporarily scuttled the production process
process selection
refers to deciding on the way production of goods or services will be organized; occurs as a matter of course when new products or services are being planned
high technology
refers to the most advanced and developed equipment and methods
DBR system
resources where capacity is a problem are specifically identified. then the various orders that are to be processed are scheduled through the capacity constraint resource (CCR) utilizing all available capacity
low level coding
restructuring the bill of materials so that multiple occurrences of a component all coincide with the lowest level at which the component occurs
poka-yoke
safeguards built into a process to reduce the possibility of errors
assembly line
standardized layout arranged according to a fixed sequence of assembly tasks
production line
standardized layout arranged according to a fixed sequence of production tasks
Master schedule
states which end items are to be produced, when these are needed, and in what quantities (also Known as master production schedule)
planned lead time =
sum of setup and run times + time buffer
summary ch 12 MRP is a planning technique that creates a schedule for all the dependent demand items in an end items bill of materials based on fixed manufacturing lead times. The end time is exploded using the BOM, and materials requirements plans are developed that show quantity and timing for ordering or producing components. The main features of mrp- time phasing of requirements, calculating component requirements, and planned order releases. To be successful, mrp requires accurate master production schedules, BOM, inventory data. A potential weakness of mrp is the assumption of constant lead times. Mrp is utilized by most MRP II and ERP systems. MRP II adds software applications design to better manage the entire manufacturing process involving finance and marketing, and including capacity planning. Erp is the 3rd generation manufacturing software that encompasses all business functions including order entry and an option for financial management integrated with the manufacturing functions available in MRP II
summary ch 12 MRP is a planning technique that creates a schedule for all the dependent demand items in an end items bill of materials based on fixed manufacturing lead times. The end time is exploded using the BOM, and materials requirements plans are developed that show quantity and timing for ordering or producing components. The main features of mrp- time phasing of requirements, calculating component requirements, and planned order releases. To be successful, mrp requires accurate master production schedules, BOM, inventory data. A potential weakness of mrp is the assumption of constant lead times. Mrp is utilized by most MRP II and ERP systems. MRP II adds software applications design to better manage the entire manufacturing process involving finance and marketing, and including capacity planning. Erp is the 3rd generation manufacturing software that encompasses all business functions including order entry and an option for financial management integrated with the manufacturing functions available in MRP II
andon
system of lights used at each work station to signal problems or slow downs
net requirements
the actual amount needed in each time period
technology
the application of scientific discoveries to the development or improvement of products and services and operations processes
facilitate a smooth flow of work, material, and info through the system 1. facilitate attainment of product or service quality 2. to use workers and space efficiently 3. to avoid bottlenecks 4. minimize material handling costs 5. eliminate unnecessary movement if workers or materials 6. minimize production or customer service time 7. to design for safety
the basic objective of layout design is to...
issues of equipment and layout and issues of workers and management
the biggest challenges of implementing cellular manufacturing involve...
takt time
the cycle time needed to match customer demand for final product
service layout design
the degree of customer contact and the degree of customization are the 2 key factors of...
technological innovation
the discovery or development of new or improved products, services, or processes for producing or providing them
group technology
the grouping into part families of items with similar design or manufacturing characteristics
1. the flow of materials through the manufacturing system should be constant and in concert with market demand. 2. the level of inventory in the plant should be reduced, and the piles of stagnant inventory should be eliminated. 3. the disruptions within the manufacturing environment must be eliminated in order to achieve a smooth production flow.
the ideal production process has three characteristics...
Why was MRP II developed?
the intent of obtaining benefits of assembly line systems in plants where assembly lines are not appropriate increase the availability and accuracy of manufacturing planning related data, the basic objective was to eliminate material shortages and operate with less total inventory in the system by getting everyone to work to one plan
cycle time
the maximum time allowed at each work station to complete its set of task on a unit
lot for lot ordering
the order or run size for each period is set equal to demand for that period; it also virtually eliminates holding costs for parts carried over to other periods
Setting the drum
the process of arriving at the planned rate of production so that it is consistent with the market demand and is within the capabilities of the constraints
line balancing
the process of assigning tasks to work stations that the work stations have approximately = time requirments
capacity requirements planning
the process of determining short range capacity requirements; the necessary inputs include planned order releases for mrp, the current shop load, routing info, and job times key outputs include load reports for each center
process batch
the quantity of a product processed at a resource before that resource changes over to make a different product.
transfer batch
the quantity of units that are moved at the same time from one resource to the next
cumulative lead time
the sum of the lead times at sequential phases of a process require, from ordering of parts or raw materials to completion of final assembly
What does the overall length of the conveyor belt in an assembly line process effectively limits?
the total amount of spreading, or work-in-process inventory
Synchronous Management Principle 6
the transfer batch need not, and many times should not, be equal to the process batch
balanced rapid flow
the ultimate goal of a lean system is a _____ _______ _____ system
computer aided manufacturing (CAM)
the use of computers and process control
economic order quantity model (EOQ)
they can lead to minimum cost if usage is fairly uniform
What is the objective of time buffers?
to provide protection for customer promise dates from the inevitable disruptions of life in the factory
gross requirements
total expected demand for an item or raw material in a time period
production marketing finance
what 3 personel work toward developing a master production schedule?
1. Capital intensity- the mix of equipment and labor that will be used by organization 2. Process flexibility- the degree to which the system can be adjusted to changes in the processing requirements due to such factors as changes in product or service design, changes in volume processed, and changes in technology
what are the 2 key aspects of an organization's process strategy?
How much variety will the process need to be able handle? How much volume will the process need to be able to handle?
what are the 2 key questions in process selection?
primary reports secondary reports
what are the 2 types of MRP outputs?
1. integrate financial data 2. standardize manufacturing processes 3. standardize HR information
what are the 3 major reasons companies undertake ERP?
production planning and scheduling, inventory management, product costing, and distribution
what does an erp system generally encompass n manufacturing environment?
minimize the sum of ordering costs ( or setup costs) and holding cost.
what is a primary goal of inventory management for both independent and dependent demand systems?
accuracy
what is essential for a successful mrp system?
continuus
when a very high volume of non discrete highly standardized output is required ( very low variety, very high volume)
repetitive
when higher volumes of more standardized goods or services are needed ( low variety, high volume)
push system
work is pushed to the next station as it is completed
pull system
work station pulls output from proceeding station as it is needed
