Operations Final Exam

Evaluating Locations, Cost-Volume-Profit Analysis process:

Determine fixed and variable costsPlot total costsDetermine lowest total costs

Cost Volume Profit Analysis: Lower volumes are best with lower _______Cost Higher volumes are best wtih lower _________Cost

FixedVariable

Methods of Evaluating Locations:

Transportation Model - Decision based on movement costs of raw materials or finished goodsFactor Rating (most popular) - Decision based on quantitative and qualitative inputsCenter of Gravity Method - Decision based on minimum distribution costs

Factor Rating/Weighted Score Model:

Wi = importance of factor iSi = score of location being evaluated on factor ii = an index for the factorsTotal weighted score = SUMi(Wi)(Si)

Using the Factor Rating Method for Location decisions, the best alternative is the one with?

Higher composite score

Center of Gravity Method of Location Decisions

Used for location of Distribution Center

Locating Pure Service Organizations

Recipient to Facility-facility utilization-travel distance per citizen-travel distance per visitFacility to Reciplient

Factors that affect Process Selection?

1. Forecasting2. Products & Service design3. Technological change4. Capacity planning5. Facilities & Equipment6. Layout7. Work design

Factors to consider when deciding to make or buy components?

1. Available capacity2. Expertise3. Quality consideration4. The nature of demand5. Cost

Process Selection based on?

Variety - how muchEquipment Flexibilty - what degreeVolume - expected output

List 5 Process types?

1. Job Shops (small runs)2. Batch Processing3. Repetitive/Assembly (semicontinuous)4. Continuous Process5. Projects (nonroutine jobs)

This process type is low volume, high variety, high flexibility?

Job Shop

This process is moderate volume, moderate variety, moderate flexibility?

Batch

This process is High Volume, Low Variety, Low Flexibility?

Repetitive Assembly (Line)

This process is very high volume, very low variety, very low flexibility?

Continuous

Describe Layout

The configuration of departments, work centers, and equipment, with particular emphasis on movement of work (customers or materials) through the system.

Three basic layout types?

1. Product Layouts2. Process Layouts3. Fixed-Position

Describe Product Layout and which processes use it?

Product Layout uses standardized processing operation to achieve smooth, rapid, high volume flow.Line, Continuous

Describe Process Layout and which processes use it?

Process layout can handle varied processing requirements.Job Shop or Batch (ex: hospital)

Describe Fixed-Position Layout and process that uses it?

Fixed Position is a layout in which the product or project remains stationary, and workers, materials, and equipment are moved as needed.Project Ex: Building or freeway

Importance of Layout Decisions?

1. Requires substantial investments of money and effort2. Involves long-term commitments3. Has significant impact on cost and efficiency of short-term operations

Eight things that cause a need for layout decisions?

1. Inefficient operations (ie: hi cost bottlenecks)2. Changes in the design of products or services3. The introduction of new products or services4. Accidents/Safety hazards5. Changes in environmental or other legal requirements6. Changes in volume of output or mix of products7. Changes in methods and equipment8. Morale problems

Layout Formats?

1. Group Technology Layout2. Just-In-Time Layouts-May be assembly-line or -Group Technology formats3. Fixed Position Layout-eg Shipbuilding

Cellular Layouts include?

1. Cellular Manufacturing2. Group Technology3. Flexible Manufacturing Systems

The advantage of Cellular Layouts?

They retain flexibility in the process and gain economies of scale.Ex: Lazyboy Case

Explain Cellular Manufacturing?

Layout in which machines are grouped into a cell that can process items that have similar processing requirements.

Explain Group Technology Layout?

The grouping into part families of items with similar design or manufacturing characteristics.

Adavantages of U-Shaped Production Line?

1. Shorter distance2. Workers can alternate tasks3. Shipping & Receiving can be in 1 place

Describe Process Layout?

Departmentalized process where work travels to dedicated process centers

Cellular Manufacturing Layout

Part families are based on Group Technology-minimizes material movement-efficient, but still flexible

Line Balancing

is the process of assigning tasks to workstations in such a way that the workstations have approximately equal time requirements.

Cycle Time

is the maximum time allowed at each workstation to complete its set of tasks on a unit.

Precendence Diagram

Tool used in line balancing to display elemental tasks and sequence requirements.

Line Balancing RulesHueuristic (intuitive) Rules

Assign tasks in order of most following tasksAssign tasks in order of greatest positional weight (positional weight is the sum of each task's time and the stimes of all following tasks)

Design Process Layouts Requirements

List of departmentsProjection of work flowsDistance between locationsAmount of money to be investedList of special considerations

What is Inventory?

A Liability (idle resource held for future useA Stock Keeping Unit (any entity that a company identifies for the purpose of control)

Types of Inventory (4)

Finished goodsWork in ProgressRaw MaterialsSpare Parts

Functions of Inventory (7)

To meet future demandTo avoid stockoutsTo meet demand in case of breakdown of equipmentHedge against price increasesDecouple production and distributionDecouple two operationsDecouple Production & Suppliers

Two basic questions of Inventory Management

How much to orderWhen to order

Independent demand

An item whose demand can be forecasted (estimated)

Dependent Demand

Demand related to the demand of other items (easier to manage, can be calculated)

ABC Classification

This method will allow you to identify the small amount of products that usually account for most of your sales dollars (think 80/20 rule)

Relevant Inventory Costs Costs increase with inventory...

Inventory Carrying Costs

Examples of Inventory Carrying Costs (6)

Cost of invested funds (interest, dividends)Cost of Storage Space (rent, heat/cool, etc)Taxes and InsuranceQuality Costs (defective units)Coordination Costs (lg lots, diff coord)Loss of Poor Responsiveness (obsolescence)

Relevant Inventory CostsCosts decrease with inventory...

Ordering Costs (Cost to place order, receive & inspect) Fixed $ amt/orderSetup Costs (item manufactured in-house)Cost of missed sales (loss of goodwill, oppty cost)

EOQ Basic Assumptions (6)

Demand is known and constantLead time is known and constantReceipt of inventory is instantaneousQuantity discounts are not possibleThe only variable costs are the cost of setting up or placing an order, and the cost of holding or storing inventory over time.Stockouts can be completely avoided if orders are placed at the appropriate time.

Formula for EOQ

Sqrt 2DS/HD=Annual DemandS=Order Cosst per yearH=Holding Cost $/unit/yr

1) Average inventory =2) # orders in a year = 3) Total Cost4) Derrivative EOQ Formula

1) 1/2Q2) D/Q3) Inventory Carrying Cost + Order Cost4) 1/2Q*H + D/Q*S

For C-Class items, the quantity is not fixed, the ________is?

period (Fixed Period Review)

Other model of inventory

Two Bin SystemReorder point is when first bin is empty

What is Lean Production?

a socioethical production system whose main objective is to eliminate waste by concurrently reducing or minimizing supplier, customer and internal variability.

Toyota Production System (TPS) idea

is to produce the kind of units needed, at the time needed, and in the quantities needed, so that unnecessary intermediate and finished product inventories can be eliminated.

Lean thinking is more than a set of techniques and approaches, it is...

a mindset for all employees and managers that focuses on waste eliminationand variability reduction in all business processes.

Who is credited with developing the original principles behind lean thinking?

Henry Ford wiht the Ford Production System (FPS)

Japanese Manufacturing approaches that drew the attention of US Manufacturers in the 70's during the US Oil Crisis

TPSJITKanbanKaizen

JIT Lean Production

Just-in-time (JIT) is a characteristic of lean production systems. JIT is a repetitive production system in which processing and movement of materials and goods occur just as they are needed, usually in small batches.JIT operates with very little fat.

Three tenets of JIT

1. Eliminate waste2. Total quality management3. People involvement

Sources of waste (6)

OperproductionWaiting timeUnnecessary transportationProcessing wasteInefficient work methodsProduct defects

Big JIT

Broad focus -Vendor relations -Human relations -Technology management -Materials and inventory management

Little JIT

Narrow Focus -Scheduling materials -Scheduling services of production

Pull System

System for moving work where a workstation pulls output from the preceding station as needed (ex: Kanban)

Push System

System for moving work where output is pushed to the next station as it is completed.

Kanban Production Control System (4)

Kanban is a card or other device that communicates demand for work or materials from the preceding station.Japanese word meaning signal or visible record.Paperless production control system.Authority to pull, or produce comes from a downstream process.

JIT in Service (describe & 6 points)

GOAL: to provide optimum response to the customer with the highest quality service and lowest possible cost.-Eliminate disruptions-Make system flexible-Reduce setup and lead times-Eliminate waste-Minimize WIP-Simplify the process

Benefits of JIT Systems (5)

Reduced inventory levelsHigh qualityFlexibilityReduced lead timesIncreased productivity

Benefits of JIT continued (5)

Increased equipment utilizationReduced scrap and reworkReduced space requirementsPressure for good vendor relationshipsReduced need for indirect labor

Kaizan

Japanese term that means contiuous improvement

Quality at the Source

a practice in which each employee is responsible for thie quality of his or her own work, therefore each person acts as his or her own quality inspector.

Jidoka

An approach for automated quality monitoring of equipment guided by a human touch.

Concurrent Engineering

a process in which multiple units/departments within an organization/supply chain are committed to working interactively to conceive, approve, develop and implement new product development programs that meet predetermined objectives.

Elements of Project Management (3)

What is a project?What is Project Management?Role of the Project Manager

What is a Project?

A set of interrelated activities necessary to achieve established goals using a specified amount of time, budget, and resources.

Primary characteristics of a Project? (6)

A well-defined goal or objectiveComposed of a set of interrelated activitiesA specified beginning and ending timeSpecified resource and personnel requirementsA specified budgetUniqueness

Project Applications (4)

Strategic projectsIntermediate range projectsShort-term projectsPersonal life projects

Examples of Operations Management Projects (3)

Developing new product offerings, ex: Wii, etcQuality Improvement Projects, ex: Six SigmaPreparation for ISO9000 certification

Project Management is...

Application of the knowledge, skills, tools, and techniques necessary to successfully complete a project.

According to PMI (Proj Mgmt Inst), project management can be divided into 5 categories...

InitiationPlanningExecutionControlClosure

Project Life Cycle (project phases) (4)

Conceptualizing - need*Planning - activities, sequence, timeOrganizing/Scheduling - detailsExecuting/Control - trade-off: resources vs. time*most time spent in the planning phase

Project Planning, Work Breakdown Structure (WBS)

Divides total work into major work packages to be accomplished, with the key being to get to the smallest possible detail.

Project Scheduling methods (2)

PERT - Program Evaluation and Review TechniqueCPM - Critical Path Method

PERT

Used for projects that have never been done beforeOptimistic / Most Likely / Pessimistic~Beta DistributionEX: Polaris Missile

CPM

Critical Path Method is an algorithm for scheduling activities within a project for the fastest and most efficient execution.

Critical Path (within CPM)

the path within a project that takes the longest time to complete.- Dictates the project completion time- aka: the bottleneck path or the binding constraint

Critical activities

the project activities making up a critical path

Slack (associated with CPM)

the amount of flexibility in scheduling an activity within a project.

Gantt Chart

A special type of horizontal bar chart used to display the schedule for an entire project.Named after Henry Gantt who originated the chart in the 1910sA Gantt Chart with different color codes can be used to track performance while the project is in progress.

Network Diagram

A diagram with arrows and nodes created to display a sequence of activities within a project.

Activity on Node (AON) approach

A network diagram that shows each activity as a circle (or a node) and connects the activities with arrows.

Activity on Arrow (AOA) convention

A network diagram in which each activity is represented by an arrow, and the nodes are used to show the beginning and end points.

Precendence Relationship

Some activities cannot be performed until other activities have been completed.

Determining the Critical Path in a network diagram

Forward pass (ES: Early Start)Backward pass (LF: Late Finish)Calculate Slack: EF= ES + activity timeLS = LF - activity timeSlack = (LS-ES) or (LF-EF)

Slack (Network Diagram)

Amount of time an activity can be delayed beyond its earliest possible starting time without delaying the project completion.

Critical Path (Network Diagram)

A chain of sequential activities beginning at the project's start and ending at its completion with the longest elapsed time. has a maximum duration compared to other paths in the network all activities on the critical path have zero slack

Project Scheduling when activity times are knownInputs (2)Outputs (5)

activity completion timesactivity precedence relationshipsgraphical representation of projecttime to complete projectidentification of critical path(s) and activitiesactivity and path slackearliest start, earliest finish, latest start,a nd latest finish times for each activity

Path Slack

Duration of Critical Path - Path Duration = Path Slack

Program Evaluation and Review Technique (PERT)

A technique for addressing the impact of uncertainties in activity time estimates on the duration of the entire project.In a project schedule, different estimates for activity times are developed: Optimistic (tO), Pessimistic (tP), Most Likely (tM), Expected (tE)

Project Scheduling when activity times are uncertainInputs (2)Outputs (4)

Optimistic (tO), Most Likely (tM), and Pessimistic (tP) time estimate for each activityActivity precedence relationshipsGraphical representation of projectExpected activity and path completion timesVariance of activity and path completion timesProbability that project completed by specified time