Operations Mgmt Final Exam
Sales and Operations Planning (S&OP)
getting marketing and operations together to set benchmarks and make decisions
Job Shop
high customization, lumpy demand
Calling Population
how many people can wait; finite or infinite?
FCFS (First Come First Served)
orders are run in the order they arrive in the department; forward scheduling; does not do especially well (or poorly) on any criteria, but is perceived as fair by customers
Lot-4-lot lot-sizing
orders just what is required for production based on net requirement -may not always be feasible - if setup costs are high, can be expensive
Master Production Schedule (MPS)
orders made, necessary production
Controlling Supply of Labor
part time employees variable work schedules shift work to slack periods increase customer participation
One-bin System
periodic check; order enough to refill bin
Supply Chain Management (SCM)
the coordination of all supply chain activities from raw materials to the satisfied customer
Two-bin System
1 bin full, 1 bin empty; order one bin of inventory when one is empty
7 wastes
1. overproduction 2. inventory 3. waiting 4. motion 5. transportation 6. rework 7. over processing
Net Requirement
= gross requirement - on hand inventory (amount needed to order)
Twenty Foot Equivalent Unit (TEU)
A standard shipping container
Water and Rocks Analogy
Boat needs to flow constantly—inventory will not just make the boat keep going; you have to actually address the issue instead of trying to cover it. 'Problems' are 'areas of opportunity' Lower the water level because inventory is a waste
Building a Supply Base
Centralized or Decentralized Purchasing -purchasing power, duplication, location Finding Suppliers -qualifications, certifications, capabilities, negotiating terms
Queue Discipline
First come, first serve Shortest processing time (quick, self-check) Reservations first (restaurants) Emergencies first (ER) Limited needs Repeat customers (amusement park)
Queue Configurations
Hospitality (multiple lines)- McDonald's, Bank, etc. Serpentine (snake line)- Wendy's, Rollercoaster, some stores Take a Number- Deli, DMV
Sourcing Issues
Make or Buy decision (setup costs or ordering costs) Many suppliers (risk mitigation, competitive pricing) Few suppliers (sole sourcing, partnerships) Vertical Integration vs. Horizontal Integration (insource vs. outsource) Keiretsu Networks (groups of many small companies) Virtual Companies (licensing) Joint Ventures
3 things needed for MRP Report
Master Production Schedule Bill of Material Master Inventory File
Aggregate Operations Plan (rough cut capacity planning--shifters)
Production Rate Changes -overtime, undertime, subcontracting (union issues) Workforce Changes -hiring/firing, training, learning curve, unemployment, COBRA, outplacement, severance, lawsuits Inventory Holding/Shortages -backorders, carrying costs, lost sales Demand Shifting -pricing strategies, promotions
Waiting Line Propositions
Prop 1: Unoccupied time feels longer than occupied time Prop 2: Preprocess Wait feels longer than in-process wait Prop 3: Anxiety makes the wait seem longer Prop 4: Uncertain waits are longer than Known, finite waits Prop 5: Unexplained Waits are longer than Explained waits Prop 6: Unfair Waits are longer than equitable waits Prop 7: The more valuable the service, the longer the customer will wait Prop 8: Solo waits feel longer than group waits
Shipping Methods
Rail- 14 Truck- 10 (fastest, most reliable) Water- 18 Pipeline- 17 Air- 16 (fast, but not reliable) Intermodal- combo of shipping methods
RFQ/RFB
Request for Quote, Request for Bid RFQ--used when deliverables are commodities for which there are clear specifications and when price will be the primary determining factor. Unlike an RFB, this solicited price quote is used for comparison purposes and is not a formal bid for work RFB--used when deliverables are commodities for which there are clear specifications and when price will be the primary determining factor
Reverse Logistics
Sending returned products back up the supply chain for resale, repair, reuse, remanufacture, recycling, or disposal
Waiting Line Models
Single Channel, Single Phase (ex: one-person barber shop) Single Channel, Multiphase (ex: car wash) Multichannel, Single Phase (ex: bank tellers) Multichannel, Multiphase (ex: hospital)
The 5 Ss
Sort/segregate- when in doubt, throw it out Simplify/straighten- methods analysis tools Shine/sweep- clean daily Standardize- remove variations Sustain/self-discipline- review work and recognize progress [2 additional Ss: Safety (built in good practices) and Support/maintenance (reduce variability and unplanned downtime)]
Toyota Production System (TPS)
Two Main Pillars: 1. JIT- most visible and highly publicized characteristic 2. Jidoka- never letting a defect pass to the next station; freeing people from machines Base: 1. Heijunka- leveling out production schedule for both volume and variety 2. Kaizen- change for better = continuous improvement 3. Standard Work- manpower, equipment, and materials used in the most efficient combination
Horizontal Integration
acquisition of a competitor
Vertical Integration
acquisition of a supplier
Lean Production
activities designed to achieve high-volume production using minimal inventories (just-in-time) -elimination of waste in production effort -value chain (each step should create value) -timing of production resources -pull, not push; (push is always going, all about production; pull is acting when needed)
Blockchain
aids tracking and verification; list of records with past data (AI)
Bill of Material
all materials needed
Planned Receipt
amount expected to come in
Planned Release
amount expected to send out
Anticipation
anticipates known future needs; produced before season of selling (ex: Christmas lights)
Finished Goods Inventory
antipation, pipeline, buffer or safety stock
Alter the Demand of Labor
appointments differential pricing
Third Party Logistics (3PL)
asset based and non-asset based; outsourcing with another party
Finite Loading schedule
capacity is considered
Infinite Loading schedule
capacity is not considered
ABC Inventory management system
catergorizing of inventory into 3 types A- large $ value, small $ volume (ex: ink cartidges) C- small $ value, large $ volume (ex: pens, paperclips) B- everything in between
Enterprise Resource Planning (ERP)
computer system integrates application programs across functions in a company (shared database) -SAP- German firm; leader in ERP software known as R3
Setup Costs
costs for arranging specific equipment setups, scrap, setup labor
Holding (carrying) Costs
costs for storage, handling, insurance, obsolescence, damage, pilferage, inventory gains and shrinkage
Shortage Costs
costs of cancelling an order, lost sales, loss of goodwill, backordering, rescheduling
Ordering Costs
costs of someone placing an order, postage, material handling, accounts receivable/payable departments, etc.
Renege
customer leaves the queue (ex: customer abandons place because the wait is too long)
Balk
customer never joins the queue (ex: driving past drivethru because line is too long)
Work in Progress (WIP) Inventory
decoupling, buffer or safety stock
Independent Demand
demand for the final end product or demand not related to other items
Dependent Demand
derived demand items for component parts, subassemblies, raw materials, etc.
Pipeline
distribution inventory; solid connection ready for distribution
EDD (Earliest Due Date)
earliest due date jobs are assigned first; backward scheduling; minimizes maximum lateness; uses CR
Supply Chain Ethics
ethical composure of every section of the supply chain
EOQ lot-sizing
expects a known constant demand -MRP systems often deal with unknown and variable demand
Supply Chain
includes suppliers, manufacturers/service providers, distributors, wholesalers, retailers, and final customers
Decoupling
increases operational flexibility; doing things ahead of time to improve cycles
Cycle Counting
inventory management system for continuous physical inventory throughout the year, usually tied to ABC classification; A's counted for frequently than C's
Critical Ratio (CR)
jobs with low critical ratios are scheduled ahead of jobs with higher critical ratios
LPT (Longest Processing Time)
jobs with the longest processing time are assigned first
SPT (Shortest Processing Time)
jobs with the shortest processing time are assigned first; does well on minimizing flow time and number of jobs in the system moves long jobs to the end which may result in dissatisfied customers
STR (Slack Time Remaining)
jobs with the shortest slack time remaining go first
Blanket Orders
large orders to just cover all needs
Master Inventory File
lead times, inventory data, purchasing data
Backward Scheduling
looks at the order due date and works backward
Raw Material Inventory
lot size inventory, buffer or safety stock
Poke Yoke
mistake-proofing methods aimed at designing fail-safe systems that minimize human error (ex: hole in sink)
MRO (maintenance, repair, and operating)
necessary to keep machinery and processes productive; not actually a part of final product
Level Production Strategy
production is set at a constant -inventory and shortages -assembly line
Chase Production Strategy
production matches demand -no inventory; exactly enough -job shop
Buffer (or safety) Stock
protection against uncertainties; uses a probability to predict; expensive and costly (so make sure it's necessary)
Gross Requirement
quantity demanded
On Hand
quantity in inventory
Electronic Funds Transfer (EFT)
quick easy money transfer
Steady Demand
regular; assembly line
Periodic Review
reviewed at fixed or equal time intervals and at each review an order may be placed; regular interval, different quantity (ex: milk every friday) note: in these problems, you're solving for the quantity to order "how many"
Johnson's Rule
scheduling a two-machine process (job shop); If the shortest processing time is on the: first machine- schedule as early as possible second machine- schedule as late as possible
Lot Size
takes advantage of quantity discounts; stuff you'll use later, sell in bulk
Forward Scheduling
takes an order and schedules it first come, first serve; pays no attention to due dates
Vendor Managed Inventories (VMI)
the company you buy from is in charge of what's in your inventory
Economic Order Quantity (EOQ)
the optimal order size to minimize the sum of ordering, carrying, and stockout costs where cost of ordering = cost of holding note: always round up
Flow time
the time between the release of a job to a work center until the job is finished
Lumpy Demand
unpredicted; job shop
Kanban System
visual signal to indicate need to order more inventory
Andon System
visual things in a factory that provide info on what's going on (ex: red light, green light)
MUDA
waste, anything other than that which adds value to product or service
Reorder Point
whenever the inventory reaches a certain, predetermined level, a fixed quantity is ordered; unequal intervals between orders (ex: toothpaste) note: in these problems, you're solving for when you need to place the order "when"