ch3.1 product design and process selection

8/7/2019 ch3.1 Product Design and Process Selection

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Chapter 3 - Product Design &

Process Selection


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Concurrent Engineering

Old over-the-wall sequential products

design process

Each function did its work and

passed it to the next function

Improved Concurrent Engineering process

All functions form a design team

that develops specifications,

involves customers early, solves

potential problems, reduces costs,

& shortens time to market

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Product Design & Process Selection -

definedProduct design the process of defining all of the companies product

characteristics

Product design must support product manufacturability (the ease

with which a product can be made)

Product design defines a products characteristics of:

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appearance,

materials,

dimensions,

tolerances, and

performance

standards.

Process Selection the development of the process necessary to produce

the designed product.


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The Product Design Process

Step 1 Planning & Idea Development - Someone thinks of a need and a

product/service design to satisfy it: customers, marketing, engineering,

competitors, benchmarking, reverse engineering

Step 2 - Product Screening - Every business needs a formal/structured

evaluation process: fit with facility and labor skills, size of market,contribution margin, break-even analysis, return on sales

Step 3 Preliminary Design and Testing - Technical specifications are

developed, prototypes built, testing starts

Step 4 Final Design - Final design based on test results, facility, equipment,

material, & labor skills defined, suppliers identified

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The Product Design Process

Idea development: all products begin with anidea whether from:

customers,

competitors or

suppliers

Reverse engineering: buying a competitorsproduct

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Product Design Process

Idea developments selection affects

Product quality

Product cost

Customer satisfaction

Overallmanufacturability the ease with which

the product can be made

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Product Screening

After a product idea has been developed it is

evaluated to determine its likelihood of

success.

Operations:What are the production needs of the proposed new productand how do they match our existing resources?

Marketing What is the potential size of the market for the proposed new

product?

How much effort will be needed to develop a market for the product ?

Finance What is the proposed new products financial potential, cost, and

return on investment?

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Product Screening Tool Break-Even

Analysis

Computes the quantity of goods company

needs to sell to cover its costs

QBE = F/ (SP - VC

) QBE Break even quantity

F Fixed costs

SP selling price/unit

VC Variable cost

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Product Screening Tool Break-Even

Analysis cont

Break-even analysis considers two functions of Q

Total cost sum of fixed and variable cost

Total cost = F + (VC)*Q

Revenue amount of money brought in from sales

Revenue = (SP) * Q

Q = number of units sold

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Break-Even Analysis: Graphical Approach

Compute quantity of goods that

must be sold to break-even

Compute total revenue at an

assumed selling price Compute fixed cost and variable

cost for several quantities

Plot the total revenue line and the

total cost line

Intersection is break-even

Sensitivity analysis can be done to

examine changes in all of the

assumptions made

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Preliminary Design and Testing

Design engineers translate general

performance specifications in to technical

specifications.

Prototypes are built and tested.

Changes are made based on test results, and

the process of revising, rebuilding a prototype,

and testing continues.


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Final Design

This is where final product specifications aredrawn up.

The final specifications are then translated into

specific processing instructions to manufacturethe product, which include selecting equipment,outlining jobs that need to be performed,identifying specific materials needed and

suppliers that will be used, and all the otheraspects of organizing the process of productproduction.


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FACTORSIMPACTINGPRODUCT

DESIGN

Design for Manufacture

Product Life Cycle

Concurrent Engineering


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2010 Wiley 14

Design for Manufacturing (DFM)

Guidelines to produce a product easily and profitably

Simplification - Minimize parts

Standardization

Design parts for multiply applications

Simplify operations


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Process

Process: Any set of activities performed by anorganization that takes inputs and transformsthem into outputs ideally of grater value to the

organization.


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Process Selection

Intermittent processes:

Processes used to produce a variety of products withdifferent processing requirements in lower volumes. (suchas healthcare facility)

Repetitive processes:

Processes used to produce one or a few standardizedproducts in high volume. (such as a cafeteria, or car wash)

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Process Types

Process types can be: Project process make a one-at-a-time product exactly to

customer specifications

Batch process small quantities of product in groups or

batches based on customer orders or specifications Line process large quantities of a standard product

Continuous process very high volumes of a fully standardproduct

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Product-Process Grid

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Intermittent VS. Repetitive Facility Layouts

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Process Selection Considerations

Process selection is based on five principal

considerations

1. Product-Process Grid

2. Degree of vertical integration

3. Flexibility of resources

4. Mix between capital & human resources

5. Degree of customer contact

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Process Decisions-Vertical Integration

Vertical integration refers to the degree a firm chooses to doprocesses itself- raw material to sales

Backward Integration means moving closer to primary

operations Forward Integration means moving closer to customers


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Linking Product Design & Process

Selection

Impact of Product Life Cycle:

Intermittent and repetitive operations typically focus onproducing products in different stages of the product lifecycle. Intermittent is best for early in product life; repetitive isbetter for later when demand is more predicable.

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Process flow analysis : A technique used for evaluating a

process in terms of the sequence of steps from inputs to

outputs with the goal of improving its design.

Process flowchart: A chart showing the sequence

of steps in producing the product or service.

Flowchart Symbols for Process Design


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Tasks or operations

Examples: Giving an

admission ticket to a

customer, installing a

engine in a car, etc.

Decision Points

Examples: How much

change should be

given to a customer

Purpose and Examples



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Examples: Sheds,

lines of people waiting

for a service, etc.

Examples: Customers

moving to a seat,

mechanic getting a

tool, etc.

Storage areas or

queues

Flows of

materials or

customers

Purpose and Examples



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Process Improvement


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Product and Service Strategy

Type of operation is directly related to product

and service strategy

T

hree basic strategies include Make-to-stock; in anticipation of demand

Assemble-to-order; built from standard

components on order

Make-to-order; produce to customer specificationat time of order


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Product and Service Strategy Options


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Flowchart for Different Product Strategies

at Antonios Pizzaria


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Process Performance Metrics

Process performance metrics defined:

Measurement of different process

characteristics that tell us how a process is

performing

Determining if a process is functioning properly is

required Determination requires measuring performance


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Process Performance Metrics

Run Time: is time required to produce a batch

of parts

SetupT

ime: is the time required to prepare amachine to make a particular item

Operation time: is the sum of the run time

and setup time

Throughput rate: The output rate that the

process is expected to produce over a period

of time


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Metrics Example: At Zelles Dry Cleaning, it takes anaverage of3 hours to dry clean & press a shirt,with value-added time estimated at110 min. Workersare paid for a 7-hour workday but work 5 hr/day,accounting for breaks and lunch. Zelles completes 25shirts per day, while the industry standard is 28 for acomparable facility.

Process Velocity = (Throughput Time)/(Value-added time)

= (210 minutes/shirt)/(110 minutes/shirt) = 1.90

Labor Utilization = (Time in Use)/(Time Available)

= (5 hr)/(7 hr) = .786 or 78.6%

Efficiency = (Actual Output)/(Standard Output)

= (25 shirts/day)/(28 shirts/day) = .89 or 89%


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Principle (Little's Law)

Little's Law says that, under steady state

conditions, the average number of items in a

queuing system equals the average rate at

which items arrive multiplied by the average

time that an item spends in the system.

WIP = Throughput Time * Throughput Rate

Throughput Time =WIP * Cycle Time


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Throughput Time

A basic process performance

metric is throughput time. A

lower throughput time means

that more products can movethrough the system. One goal of

process improvement is to

reduce throughput time.

ch3.1 product design and process selection

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