MPD 575
Design for Serviceability
Jonathan Weaver
1
• Pg 3 3rd line, "At" should be "at"
• Pg 3 4th line from bottom, "Of" should
be "of"
• Pg 48 "earth" should be "Earth"
• Pg 59 "design" should be "designs"
• Pg 59 "lead" should be "led"
• Pg 63 "engines" should be "engine's"
2
Development History
• Originally developed by Cohort 1 team of
Henry Brown, David Ogbuaku, and Vince
Croom
• Critiqued and Improved by Cohort 1 team:
Steve Borkes, Larry Liotino, and Dennis
Person
• Critiqued and Improved by Cohort 2 team:
Tom Jones, James Watson, and Doug
Schrandt
3
Intro Humor
A few days ago a gentleman was having some work
done at his local garage. A blonde came in and asked
for a seven-hundred-ten. They all looked at each
other, and another customer asked, "What is a
seven-hundred-ten?" She replied, "You know, the
little piece in the middle of the engine, I lost it and
need a new one. It had always been there." The
mechanic gave the blonde a piece of paper and a
pen and asked her to draw what the piece looked
like. She drew a circle and in the middle of it wrote
710. He then took her over to another car which had
the hood up and asked, "is there a 710 on this car?"
She pointed and said, "Of course, its right there."
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Intro Humor (Cont.)
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Design for Serviceability(DFS)
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Introduction to DFS
Why DFS?
DFS and the Customer
Impact of DFS
Serviceability Concerns
Guidelines for DFS
DFS Process
Other DFS Needs
Useful DFS Data and Tools
Software
Examples
Summary
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Design for Serviceability (DFS)
Introduction
"In the Ford Motor Company we emphasize service equal with
sales...It has always been our belief that a sale does not complete
the transaction between us and the buyer, but establishes a new
obligation on us to see that his car gives service... We are as
much interested in your economical operation of the car as you
are in the economical manufacture of it... This is only good
business on our part... If our car gives service, sales will take care
of themselves... For that reason we have installed a system of
controlled service to take care of all Ford car needs in an
economical and improved manner... We wish all users of Ford
cars to know what they are entitled to."
Henry Ford
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Design for Serviceability (DFS)
Introduction
• Service is defined as:
– the occupation or function of serving; to
perform services for: as to repair or provide
maintenance for, to perform any of the
business functions auxiliary to production
or distribution.
Source: Webster’s Dictionary
8
Design for Serviceability (DFS)
Introduction
• Serviceability, according to Ford Motor
Company, is defined as:
– The ability to diagnose, remove, replace,
replenish, adjust, or repair any component
or subsystem, to optimum specification,
with relative ease.
Source: Ford Motor Company DFIS Manual
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Design for Serviceability (DFS)
Introduction
• By extrapolation, Design for
Serviceability is defined as: the practice
of considering service and serviceability
as part of the design process.
• The process of optimizing a product for
serviceability is fundamentally different
from that of optimizing it for ease of
initial assembly.
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Design for Serviceability (DFS)
Why DFS?
• To achieve and maintain leadership,
businesses must satisfy their customer and at
the same time control costs, a challenging
task.
• A great many elements make up customer
satisfaction: product cost, performance,
styling and quality.
• Quality includes not only conformance to
specification, measured by fit and function,
but also the quality of the vehicle over time,
usually measured as life cycle cost.
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Design for Serviceability (DFS)
Why DFS?
• Along with these technical elements, products
must also be manufactured to create an
enjoyable ownership experience to keep
customers happy and coming back.
• One major obstacle to customer satisfaction
is the cost of maintenance and service, and
the aggravation they both create.
• Warranty is a major cost in the product life
cycle, thus both manufacturers and
customers are interested in the serviceability
of the product.
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Design for Serviceability (DFS)
Why DFS?
• Proper application of DFS methods can decrease total life costs
and increase the bottom line.
• Serviceability must be considered early in the design cycle.
• "Serviceability reviews often occur late in the development
process when the design is quite firm and changes are costly."
(source: Design Theory and Methodology DTM ’91)
• 70% of the life cycle costs are committed by the time of concept
formulation, rising to 85% by the start of development before
any hardware is built. (source: Design for Serviceability Expert System )
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Design for Serviceability (DFS)
DFS and the Customer - Stakeholders
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Distribution System (Dealers)
D-I-Y (Do It Yourself) Owners…You!!
Manufacturing / Assembly Plants
Third-party Service Providers
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Design for Serviceability (DFS)
DFS and the Customer - Buying Motives
• A study conducted by Tenneco Corp. to
identify customer buying motives found
that the number one factor in the buying
decision was a well-constructed, high
quality product.
• Three of the top five buying motives
involved quality product service.
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Design for Serviceability (DFS)
DFS and the Customer - Buying Motives
• Among the top five buying motives,
customers identified:
– Quality
– Repair work
– Repair when promised
– Quick service response
(source: 1989 ASQC Quality Congress Transactions)
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Design for Serviceability (DFS)
DFS and the Customer - Desires
• When it comes to service, customers
desire no service at all.
• To satisfy customers from a
serviceability view, the manufacturer
should design for:
– Reliability
– Minimal maintenance
– D-I-Y (Do It Yourself) maintenance
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Design for Serviceability (DFS)
DFS and the Customer - Satisfaction & Loyalty
• It cost five times as much to gain one new
customer as it does to retain one.
• Satisfied customers tell eight to ten others.
• Dissatisfied customers tell 16 to 20 others.
• Twenty-five percent of the dissatisfied
customers may tell as many as 40 other
people.
(source: Automotive News)
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Design for Serviceability (DFS)
DFS and the Customer - Satisfaction & Loyalty
• If service is required, customers expect it to be with
relative ease and minimal cost.
• To maintain customer satisfaction and loyalty, repair
time and cost must be minimized. For the
manufacturer this means:
– Repairs should be continuously reduced.
– Repair time reduction depends on solid diagnostics, ease of
access, simplicity and standardization.
– The final cost of a repair must be reduced.
• Excellent serviceability helps a company develop and
maintain customer satisfaction and loyalty.
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Design for Serviceability (DFS)
DFS and the Customer - Satisfaction & Loyalty
• Poor serviceability leads to customer
dissatisfaction through higher costs and
longer repair time resulting in lost sales
and market share for the manufacturer.
• To maintain customer satisfaction and
loyalty, manufacturers should provide a
high level of product serviceability.
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Design for Serviceability (DFS)
DFS and the Customer - Satisfaction & Loyalty
• Customers expect superior service from major
service and repairs to minor adjustments.
• The following measured costs have a strong
correlation with serviceability:
– Operating costs
– Scheduled maintenance and repair costs
– Unscheduled maintenance and repair costs
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Design for Serviceability (DFS)
DFS and the Customer - Satisfaction & Loyalty
Customers look at total cost of ownership. If a product
needs repair the owner cares about how often the
repair must be done, how long it takes to complete the
work (the aggravation factor) as well as how much it
costs.
– Costs not covered under warranty, or incurred after the
warranty expires, increase customer dissatisfaction.
– In the automotive industry, estimated life cycle repair costs
are three to four times the warranty costs. One of the ratings
for used cars in Consumer Digest is the average cost of
repairs. A cost index rating shows how each make and
model’s repair costs stack up against the competition.
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Design for Serviceability (DFS)
Impact of DFS
Design for Serviceability requires considering
associated costs of factory corrections of
defects, campaigns, litigation, buy-backs,
distribution support, and warranty costs.
– Reduction in company warranty expenses
– Reduction in “customer pay” expenses
– Reduction in other hidden costs
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Design for Serviceability (DFS)
Impact of DFS
Impact on Manufacturers:
• Warranty Improvement
• Strengthened Brand Image
• Enhanced Residual Vehicle Values
• Increased Profitability
Impact on Customer:
• Improved Satisfaction
• Reduced Cost of Repairs
• Added Convenience
• Improved Diagnostics (faster problem diagnosis leads to faster and
less expensive repair)
• Reduced Part Pricing
• Improved Resale Value
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Design for Serviceability (DFS)
Serviceability Concerns
OEM concerns:
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Parts Cost: What will be the cost of the replacement parts?
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Frequency: How often will the component require service?
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Labor Time: How long will the service take?
Owner concerns:
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Latent Failure: What is the potential for causing a latent failure
from the service procedure?
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Repeat Repair: What is the potential for having to repair it over?
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Performance Level: Will the original vehicle performance level be
restored?
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Customer Expectation: Will the customer be satisfied with the
service?
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Design for Serviceability (DFS)
Serviceability Concerns
Technician concerns
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Safety: Are there any safety concerns related to service of the
component?
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Damage: What is the potential for damaging other components
during service?
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Diagnosis: Are diagnostics required? Can they be performed?
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Special Tools: Are special tools necessary?
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Reasonableness: Is the service procedure correct for the type of
service required and is the procedure straightforward?
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Labor Time: How long will the service take?
For the technician, all of these are a result of accurate training and
well written service reference manuals.
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Design for Serviceability (DFS)
Guidelines for DFS
Minimize the number of layers of components.
• Results in a reduction in the maximum number of
components removed to gain access to a specific part.
Design the components that are most likely to
fail or need servicing close to the assembly
surface.
• Results in a cost reduction of the most frequent service
operations.
Develop a modular product structure.
• Whole sub-assemblies may be removed and replaced
instead of individual, embedded components.
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Design for Serviceability (DFS)
Guidelines for DFS
Minimize the number of connections between
sub-assemblies.
• The time and complexity to remove and install subassemblies is reduced.
Use standard components.
• Results in component cost reduction, availability of parts,
a reduction in the use of specialty tools, a reduction in the
variety of tools needed and reduction of time lost to
acquire custom components. Additionally, component
characteristics are better predicted.
Minimize specialist labor.
• Easy problem diagnostics and use of common
components allows for servicing by a general technician.
Source: U. of Queensland Manufacturing website
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Design for Serviceability (DFS)
DFS Process
Determine Initial Serviceability
Requirements
Define the product serviceability:
•Needs
•Requirements
•Restrictions
In addition, what serviceability improvements are
needed from the last design?
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Design for Serviceability (DFS)
DFS Process
Determine Data Qualifiers for Serviceability
• Determine the product’s level of serviceability from past
designs and industry benchmarks.
• Establish if the product is intended to be serviced by the
customer, service centers, the manufacturer or not at all.
Components that are regularly serviced by the vehicle owners
will have different requirements than those serviced by
technicians.
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Design for Serviceability (DFS)
DFS Process
Review the Design’s Serviceability
A series of checklists should be implemented for serviceability
review with the following headings:
• Location
• Simplification
• Standardization
• Design for Repair
• Life Factors
• Diagnostics
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Design for Serviceability (DFS)
DFS Process
Review the Design’s Serviceability
There are sub-headings, with accompanying questions, under
each of the main headings. The sub-headings are as follows:
• Location - Accessibility, Obstructions, Orientation, Visibility
• Simplification - Minimization, Clustering, Labeling, Intuitive
• Standardization - Components and Sub-components, Fasteners and
Connectors, Tools
• Design for Repair - Ergonomics, Service Aids, Obvious Operation,
Safety
• Life Factors - Reaction, Mechanical Stress, Environment, Location,
Component Retirement
• Diagnostics - Indicators, Accessibility, Procedures
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Design for Serviceability (DFS)
DFS Process
Location Checklist
Accessibility
– Is the component layer based on service frequency
and user?
– Can the component be reached with hands?
– Can the component be reached with normal tools?
– Can the component be removed from its location?
– Can the components be grouped for better
serviceability?
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Design for Serviceability (DFS)
DFS Process
Location Checklist
Obstructions
– Do other components have to be removed for
visibility, service, or removal?
– Is there potential for damage of nearby
components in the service process?
– Can you offer more space by moving, hiding, or
shrinking the component or adjacent component?
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Design for Serviceability (DFS)
DFS Process
Location Checklist
Orientation
– Do the service steps require multiple re-orientations?
– Can any fluids be retained in the process?
– Will Service expose other parts to contamination?
Visibility
– Can the component be clearly seen for diagnosis and/or
removal/installation?
– Does the layout look BIC (Best in Class)?
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Design for Serviceability (DFS)
DFS Process
Simplification Checklist
Minimization
– Have you reduced part count with DFA
(Design for Assembly)?
– Have you reduced or eliminated user
adjustments?
Clustering
– Is the component located where expected?
– Is the component grouped with like functions?
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Design for Serviceability (DFS)
DFS Process
Simplification Checklist
Labeling
– Does the component have clear instructions?
– Is the component color coded?
Intuitive
– Is the disassembly obvious?
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Design for Serviceability (DFS)
DFS Process
Standardization Checklist
Components and Sub-Components
– Can you use an industry standard component or subcomponent?
– Can this component be used on other platforms?
– Is the component backward/forward compatible?
Fasteners and Connectors
– Are the fasteners/connectors the same type, size, length?
Do they match other assemblies?
– Are the fastener orientations the same?
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Design for Serviceability (DFS)
DFS Process
Standardization Checklist
Tools
– Can you service with a minimum of tools?
– Can you service without a need for special tools?
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Design for Serviceability (DFS)
DFS Process
Standardization Checklist
Ergonomics
– Can the component be manipulated or removed by
hand?
– Are the torques within normal user limits?
– Have you protected against human-caused failure?
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Design for Serviceability (DFS)
DFS Process
Standardization Checklist
Service Aids
– Have you included guides and assembly aids:
locators, pilots, adhesives, sealants, etc. to make
assembly easier?
– Have you incorporated anti-cross threading?
– Have you included adjusting, lifting, pry points?
– Can you replace what’s broken?
– Must you damage or break components to perform
repairs?
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Design for Serviceability (DFS)
DFS Process
Design For Repair Checklist
Obvious Operation
– Can the parts only locate the “right” way?
– Is the disassembly/reassembly order mechanically
constrained?
– Does your design indicate when the repair is correct?
Safety
– Have you eliminated sharp edges?
– Have you guarded against shock hazards?
– Have you protected against stored energy - loaded
springs, pressurized fluids and explosives?
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Design for Serviceability (DFS)
DFS Process
Life Factors Checklist
Reaction:
– Have you protected against failure from corrosion,
galvanic interaction, and reaction with engine and
service fluids?
Mechanical Stress:
– Have you protected against vibration, stress, and
thermal expansion?
Environment
– Have you protected against failure from temperature,
ultraviolet, moisture, dirt, and dust?
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Design for Serviceability (DFS)
DFS Process
Life Factors Checklist
Location
– Does the component need to be located for cooling?
– Is the component protected from collision damage?
Component Retirement
– Can the component be designed to be recycled or
remanufactured?
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Design for Serviceability (DFS)
DFS Process
Diagnostics Checklist
Indicators
– Have you included maintenance required indicators?
– Have you included wear limit, repair, or failure indicators?
Accessibility
– Does package environment allow diagnostics to be
performed with non or limited movement of other
components?
Procedures
– Have you suggested diagnostic procedures?
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Design for Serviceability (DFS)
DFS Process
Investigate Opportunities for Improvement
• What are our customers telling us they want or need?
• What are the existing problems?
• What suggestions do our internal experts recommend?
• What are we (and our competitors) doing right that we can
use?
• What are we (and our competitors) doing wrong that we can
avoid?
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Design for Serviceability (DFS)
DFS Process
Integrate Serviceability into the Design
• The first way to improve serviceability is to minimize the need
for service.
• Use warranty and reliability data to determine failure rates
and Pareto ranking to determine priorities.
• Use design techniques aimed at increased reliability:
Long -life materials and sub-components
Reduction of stresses and variations of stresses
Design for stiffness
Minimize Part Count (DFA/DFM)
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Design for Serviceability (DFS)
Other DFS Needs
Other considerations that are not precisely part of that
discipline, but have a direct bearing on design for
serviceability:
• Styling - Styling, craftsmanship and serviceability must be balanced.
Innovative designs generate increased need for out-of-the-box thinking to
obtain acceptable serviceability.
• Appearance - For the consumer who is service conscious, the design
of the product must not only be easy to service, it must look easy to
service. Many first-time purchases are made on perceptions.
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Design for Serviceability (DFS)
Other DFS Needs
• Damageability - Designs must consider damage repair. Expensive
and delicate parts must be positioned for protection against damage. The
ability to easily disassemble units and only replace damaged elements
will reduce labor times and cost to repair. Insurance repair costs are
increasingly being used for large purchase evaluations by customers.
• Design for Recycleability - With the increasing awareness of our
environment, customers are demanding that products be “Earth
conscious.” Recycleability is rapidly becoming the law. That means the
manufacturer needs to consider using recycled raw materials and
increase the ability to reuse or recycle product components that are
removed during servicing or maintenance.
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Design for Serviceability (DFS)
Useful DFS Data and Tools
Data
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Warranty Data
Serviceability Targets
Design Manuals
TSB (Technical Service Bulletins)
TGR/TGW Lists
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Design for Serviceability (DFS)
Useful DFS Data and Tools
Tools
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R/1000
FMEA
DFA/DFM
Benchmarking
8D’s (Eight Disciplines) [A Ford Motor Company Process]
Reliability/Life Analysis
Models (Continuous Improvement Process, etc.)
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Design for Serviceability (DFS)
Software
One DFS software product is marketed by Boothroyd Dewhurst,
Inc. The same results may be obtained by developing an Excel
spread sheet with the proper parameters.
• The software provides the user with a series of reports, including a
Suggestions for Redesign report which highlights and prioritizes
areas in the service task which should be examined for service
improvement.
• The benefits of conducting a DFS analysis include reduced
warranty costs, improved customer satisfaction, and more
environmentally sensitive products due to longer life through
economical servicing.
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Design for Serviceability (DFS)
Software
The benefits of DFS software according to Dr. Peter Dewhurst of
Boothroyd Dewhurst, Inc. are:
“DFS software provides the type of systematic method that will allow
the user to step through the process and look at the service tasks and
recognize problems up front.”
The methodology for a DFS analysis is:
• Identify each service item and choose a disassembly sequence (the reassembly
sequence is automatically generated based by the software)
• Perform a more detailed analyses of the parts with special service requirements such
as corrosion
The software renders an analyses on service tasks with estimates of the
total disassembly and reassembly time, a serviceability rating and
identification of serviceability costs such as labor, operation steps, and
part replacement costs.
Appliance Manufacturer, Nov. 1993 v41 n11 p69(1)
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Design for Serviceability (DFS)
EXAMPLES
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Design for Serviceability (DFS)
• Financial example for DFS:
Independent Tests Prove Toshiba’s Equium
Desktops Lead the Industry in Serviceability
and Reducing TCO (Total Cost of Ownership)
This is mainly attributed to a patent-pending
one-touch “Instant Access” door.
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Design for Serviceability (DFS)
• Financial example for DFS: (continued)
Excerpts from the article:
Equium 7100 series beat the competition in
five tests designed to measure business TCO
expenses including upgrading memory,
upgrading motherboard, replacing hard drive,
replacing CD-ROM drive and creating and
installing a software pre-install image.
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Design for Serviceability (DFS)
• Financial example for DFS: (continued)
Equium 7100 series can reduce PC staffing
costs by up to 8.8% or $433 per PC per year.
This equates to a total cost savings of
$433,000 annually per one thousand seats.
Business Wire, July 7, 1999 p0020
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Design for Serviceability (DFS)
Glue as a Serviceability Aid
In an article (advertisement in disguise) about the
creative use of adhesives, Loctite describes how
conformal silicates can replace gaskets in an air
pump assembly. The highlights are:
A DFA analyses was conducted to demonstrate the savings in
time and costs between conventional gaskets and formed-inplace gaskets of silicone.
A second analyses was performed to evaluate the formed-inplace gaskets if they were installed in a separate station.
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Design for Serviceability (DFS)
Glue as a Serviceability Aid (continued)
The serviceability applicable details of the article are reflected in
the data as 13% percent less service time because the gaskets
are no longer handled as separate parts but are now in place
on the sealed components.
An additional feature applicable to DFS is that silicone to
silicone seals are more resistant to leaks and environmental
degradation than the comparator gasket leading to longer
service intervals, both planned and unplanned.
Appliance Manufacturer, Nov. 1994 v42 n11 p42(2)
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Design for Serviceability (DFS)
Diesel design in the 1980s
Three new diesel engine designs were created in the 1980s with
serviceability in mind. This led to a simpler engine design with
easier manufacturability in addition to improved serviceability.
The new designs were:
• Detroit Diesel 60 series engines
• Cummins B & C series engines
• Caterpillar 3176 series 11.1 and 12.7 liter engines
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Design for Serviceability (DFS)
Diesel design in the 1980s (continued)
Detroit Diesel 60 series engine serviceability features:
• The engines were electronically controlled which allowed for a
diagnostic system that determined the problem quickly and
accurately so that the correct part was serviced the first time.
• The system self checks each time at engine start to make sure
that all sensors, warning lights and electronics are functioning
properly.
• Electronic control module and sensors are located on one side
of the engine compartment.
• The hand-held diagnostic reader is reprogrammable for
updates and upgrades.
61
Design for Serviceability (DFS)
Diesel design in the 1980s (continued)
Detroit Diesel 60 series engine serviceability features:
• The engines were colored blue to assist in identifying bolts and
fluid leaks. The bolts were not painted at all so that the bolt
heads would not get gummed up by paint which sometimes
prevented sockets from fitting correctly.
• The cap screw lengths were varied by at least 10mm to allow
for easy identification of a particular bolt.
• The 11.1 and 12.7 liter engines have only 450 different parts
and are separated by only 8 different part numbers.
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Design for Serviceability (DFS)
Diesel design in the 1980s (continued)
Cummins B & C series engine serviceability features:
• 600 parts for the B series and 620 parts for the C series
achieved through part consolidation.
• The water pump inlet and volute, oil cooler, oil pump housing
and coolant bypass line are all cast into the engine block.
• Designed for the “Backyard mechanic” by eliminating the need
for any special tools during servicing.
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Design for Serviceability (DFS)
Diesel design in the 1980s (continued)
Caterpillar 3176 series 11.1 and 12.7 liter engine
serviceability features:
• Part consolidation by commonizing between engines roller and
sleeve bearings, O-rings and gaskets. This also minimized the
number of special tools required for maintenance.
• The gear-type oil pump on the 3116 engine is a separate unit
mounted at the front of the engine below the cylinder block.
This allows the pump to be removed without removing the front
cover or the timing gear train.
64
Design for Serviceability (DFS)
Diesel design in the 1980s (continued)
Caterpillar 3176 series 11.1 and 12.7 liter engine
serviceability features:
• Poly-V belts are used with spring loaded belt-tensioners. This
allows the belts to be self adjusting and can be installed or
removed in minutes.
• Gaskets are avoided where ever possible and O-rings are used
at all pressure lubrication joints.
65
Design for Serviceability (DFS)
New Holland Tractors
• Swing-out access door on each
side of the hood for routine
maintenance. Deere access
panels are difficult to remove
and tethered to the frame by a
cable.
• Flip-up hood that gives total
access to the entire engine.
66
Design for Serviceability (DFS)
New Holland Tractors (Cont.)
 Swing open instant access to the radiator (Deere requires
bolt removal).
 Self-adjusting belt for A/C and alternator (Deere hard to
access; requires adjustment)
 Fuel filter is vertical (Deere’s is horizontal leading to fuel
spills)
 Common reservoir and screen for transmission and rear
axle (Deere uses two)
67
Design for Serviceability (DFS)
1999+ Concorde/Intrepid
Powertrain
• The 2.7-liter engine oil filter base is integral with the oil pan, preventing spillage
during filter changes, and minimizing residual left in the block
• The oil filter on the 2.7-liter engines is more accessible than on prior engines
• The 2.7-liter engine includes a trough in the valve cover around the oil filler cap
nipple that keeps spilled oil (during filling) from running down the side of the
block
• Increased accessibility to upper bell housing bolts makes transaxle removal
easier
• A new rear transmission mount simplifies mount replacement and improves
transaxle removal
• Coil-on-plug ignition eliminates spark plug wires and simplifies tune-ups
• Platinum-tipped spark plugs provide 100,000 mile tune-up intervals under
normal operating conditions
• New exhaust system clamps do not crush pipes together, making pipe
separation simple.
68
Design for Serviceability (DFS)
1999+ Concorde/Intrepid (Cont.)
Suspension and Steering
• New steering tie rod ends make toe adjustment easier
• New rear suspension design and fuel tank placement
simplifies tank removal
• Front stabilizer bar service no longer requires the removal of
engine cradle from vehicle
• Removal of rear stabilizer bar no longer requires removal of
the gas tank
• A translucent power steering fluid reservoir allows the fluid
level to be checked without removing the cap
69
Design for Serviceability (DFS)
1999+ Concorde/Intrepid (Cont.)
Brakes
• The modular anti-lock brake system, which places both electronic
controls and the valve unit in the same location, is both easier to
diagnose and service
• New parking brake cable routing along the door sill makes replacement
easier
Engine Cooling
• A carbon seal on the water pump provides life-of-the-vehicle endurance
• Long life engine coolant thermostat designed to last 7 years or 100,000
miles
• Long-life engine coolant extends the change interval to 5 years or
100,000 miles under normal operating conditions
70
Design for Serviceability (DFS)
1999+ Concorde/Intrepid (Cont.)
Body
• A new steering column mounting system requires removal
of only the steering column cover needs to access the
column
Diagnostics
• Diagnostic communications use the new industry standard
J1850 data bus, providing access to on-board diagnostic
information by aftermarket scan tools
• Odometer readings display briefly when any door is opened
to facilitate checking by service attendants
71
Design for Serviceability (DFS)
Saturn Serviceability Features
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•
•
•
•
•
•
•
•
Distinctive color-coded dipsticks.
Quick-Glance transparent fluid containers.
Easy access sparkplugs.
Easy replacement air, oil, and transmission filters.
Easy access under-hood fuse box.
Maintenance-free battery.
Self-adjusting accessory belt.
Quick-change headlamp bulbs.
Handy gas cap holder.
72
Design for Serviceability (DFS)
Good example of Heater Core Removal
Remove the heater air plenum chamber
(18471) assembly as described.
1.
Remove the four retaining screws (1)
from the heater core cover (18B300) and
remove the heater core cover (6) from the
heater air plenum chamber assembly.
2.
Pull the heater core (18476) assembly
from the heater air plenum chamber
assembly.
Note: There seems to be more steps to this
process, removing the hose connections
for example, but it is a top removing plan
for service which does not require under
the car servicing like the next example.
73
Design for Serviceability (DFS)
Bad example of Heater Core Removal
1. Remove heater outlet floor duct (18C433) as described.
2. Raise vehicle. Refer to «Section 00-02».
3. Disconnect heater water hoses (18472) from heater core
inlet and outlet tubes. Plug heater water hose and cap
heater core tubes to prevent coolant loss during removal
of heater core (18476).
4. Disconnect vacuum supply hose (black) from vacuum
source in engine compartment.
5. Lower vehicle.
6. Disconnect vacuum supply hose (black) from A/C
vacuum reservoir tank and bracket (19A566) inside
vehicle.
7. Release four retaining tabs, remove two clips and
remove heater core cover containing heater core, and
vacuum hose (18666) from vehicle.
8. Remove heater dash panel seal (18529) and vacuum hose
from heater core cover.
9. Remove retaining screw and heater core mounting
bracket from heater core cover.
10.Remove heater core from heater core cover.
11.Remove heater core case seal (18658) from heater core.
12.To install, reverse Removal procedure.
74
Design for Serviceability (DFS)
1975 – 1987 GM HEI Electronic Ignition System
Good example of Design for Serviceability
75
Design for Serviceability (DFS)
1975 – 1987 GM HEI Electronic Ignition System
76
Design for Serviceability (DFS)
1977 – 1987 Ford Dura - Spark Electronic Ignition System
More complicated Design for Serviceability scheme
77
Design for Serviceability (DFS)
Good example of Design for Serviceability
Removal
1.
Remove approximately one-third of the brake fluid from the
brake master cylinder (2140). This will prevent fluid
overflow when the caliper piston is pressed into the cylinder
bore.
2.
Raise and support the vehicle.
3.
Remove the wheel and tire assembly.
4.
Remove the disc brake pad anti-rattle clip (2B164).
5.
Disengage the M-shaped anti-rattle spring from the brake
shoes and linings (2001).
6.
Remove the two disc brake caliper locating pins (2B296) and
the M-shaped anti-rattle spring.
Note: Do not discard the shims found behind the brake shoes and
linings. Remove the brake shoes and linings and the shims.
This service procedure is much less complicated than
the following example.
78
Design for Serviceability (DFS)
Bad example of Design for Serviceability
Removal
Refer to the illustration under «Caliper Installation».
1.
Remove brake master cylinder cap and check fluid level in
brake master cylinder reservoir (2K478). Remove brake fluid
until brake master cylinder reservoir is half full. Discard
removed fluid.
2.
Raise vehicle on hoist.
3.
Remove wheel and tire assembly. Use care to avoid damage or
interference with front disc brake rotor shield (2K005) or wheel
cylinder bleeder screw (2208).
4.
Measure run out and rotor thickness.
5.
Note: It is not necessary to disconnect hydraulic connections to
replace brake shoe and lining (2001).
For 15 inch wheels -- Remove front disc brake caliper bolt
(2W303) from disc brake caliper (2B120).
For 16 inch wheels -- Remove lower brake pin retainer from
disc brake caliper.
6.
For 15 inch wheels -- rotate disc brake caliper up and away from front disc brake caliper anchor plate (2B292) and
front disc brake rotor (1125) pivoting on the disc brake caliper locating pin (2B296).
7.
Support the disc brake caliper assembly in a manner that will not stretch or damage the front brake hose (2078). Be
sure shoe and linings stay in the front disc brake caliper anchor plate.
8.
Remove outer and inner brake shoe and lining assembly from front disc brake caliper anchor plate.
9.
Inspect both front disc brake rotor braking surfaces. Minor scoring or buildup of brake shoe and lining material does
not require machining or replacement of front disc brake rotor. Remove glaze from both front disc brake rotor
braking surfaces by hand-sanding with garnet paper 100A (medium-grit) or aluminum oxide 150-J (medium).
10.
Inspect piston boot and caliper pin boots for damage and replace as necessary.
79
Design for Serviceability (DFS)
Ignition Switch Removal
Good example of DFS
1.
2.
3.
4.
5.
Disconnect the battery ground cable.
Pull the steering column opening cover off the lower instrument
panel (04320).
Locate the ignition switch above the driver side knee brace and the
steering column opening reinforcement.
Disconnect the wiring harness from the ignition switch.
Remove the ignition switch screws and the ignition switch.
80
Design for Serviceability (DFS)
Ignition Switch Removal
Poor example of DFS
1.
2.
3.
4.
5.
6.
7.
8.
Disconnect the battery ground cable.
Remove the parking brake release handle.
Remove the hood latch release handle.
Remove the lower instrument panel steering column
cover.
Remove the instrument panel steering column opening
cover reinforcement (04502).
Remove the instrument panel steering column opening
cover reinforcement.
Disconnect the ignition switch electrical connector.
Remove the ignition switch.
81
Design for Serviceability (DFS)
Oil Fill Cap/Tube
LOCATION CHECKLIST
• Accessibility, obstruction – Cap and tube
access is blocked on three sides.
• Visibility – visibility is poor because the
tube opening is the same color as the
surrounding area when the cap is removed.
SIMPLIFICATION CHECKLIST
• Clustering – the oil dip stick is not local to
this filling tube.
• Labeling – cap does have clear
labeling
• DESIGN FOR REPAIR CHECKLIST
• Ergonomics – Cap rotation and oil pour is
not easily accomplished.
82
Design for Serviceability (DFS)
Oil Filler Tube
(continued)
LOCATION CHECKLIST
• Visibility – visibility is poor
because the tube opening is the
same color as the surrounding area
when the cap is removed.
83
Design for Serviceability (DFS)
Oil Filler Tube
(continued)
LOCATION CHECKLIST
•Accessibility, obstruction – Cap
and tube access is blocked on
three sides.
DESIGN FOR REPAIR CHECKLIST
•Ergonomics – Cap rotation and
oil pour is not easily
accomplished.
84
Design for Serviceability (DFS)
Oil Filler Tube
(continued)
DESIGN FOR REPAIR CHECKLIST
• Ergonomics – Cap rotation and oil pour is not
easily accomplished.
Two of three possible positions for oil refill demand an incorrect
bottle position.
85
Design for Serviceability (DFS)
Oil Filler Tube
(continued)
Oil refill in correct
bottle position but there
are no directions on the
bottle or on the vehicle
to demonstrate this.
86
Design for Serviceability (DFS)
Oil Stick
LOCATION CHECKLIST
•Accessibility, obstruction – Dip stick access
is blocked on three sides.
•Visibility – visibility is poor because the
tube opening is the same color as the
surrounding area when the dip stick is
removed.
SIMPLIFICATION CHECKLIST
•Clustering – the oil filling tube is not local
to this dip stick.
•DESIGN FOR REPAIR CHECKLIST
•Ergonomics – Dip stick reinsertion is not
easily accomplished.
SIMPLIFICATION CHECKLIST
•Labeling – handle has clear
labeling
87
Design for Serviceability (DFS)
Oil Stick
(continued)
LOCATION CHECKLIST
•Visibility – visibility is poor because
the tube opening is the same color as
the surrounding area when the dip
stick is removed.
•DESIGN FOR REPAIR
CHECKLIST
•Ergonomics – Dip stick reinsertion is
not easily accomplished.
88
Design for Serviceability (DFS)
Oil Filter
LOCATION CHECKLIST
• Accessibility – Oil filter is not easily
accessed for replacement.
• Obstruction – Oil filter is accessed only
through a narrow slot and degree of rotation
with a tool is restricted.
• Orientation – Oil filter is oriented for oil
drainage but not for the safety of the operator.
• Visibility – Engine side threads for the oil
filter are not visible.
DESIGN FOR REPAIR CHECKLIST
• Ergonomics – Surrounding obstructions
make filter replacement difficult.
• Safety – Oil flow during removal and when
the filter is removed is not controllable.
89
Design for Serviceability (DFS)
Oil Pan Drain Plug
LOCATION CHECKLIST
• Accessibility, obstruction – Oil valve is easily
accessed. Removal is open for about 180 degrees of
turn for a tool.
• Visibility – Oil valve is clear and obvious but the
addition of color to the head would improve its
visibility.
DESIGN FOR REPAIR CHECKLIST
• Ergonomics – Given that the valve is on the
underside of the car, it is relatively easy to access,
remove and return to position.
• Obvious Operation – The oil valve removal is
obvious by the shape of the head.
• Safety – The operator has considerable room to
work but a warning about hot conditions would be
appropriate.
90
Design for Serviceability (DFS)
Master Cylinder
SIMPLIFICATION CHECKLIST
• Clustering – The reservoir is
located near the master cylinder
• Labeling – The labeling on the cap
should be painted. Also, there are too
many letters so the character size is
quite small making the text hard to
read.
91
Design for Serviceability (DFS)
Master Cylinder
(continued)
SIMPLIFICATION CHECKLIST
• Labeling – The reservoir has no
labeling to tell its function when the
cap is removed.
92
Design for Serviceability (DFS)
Power Steering Pump Reservoir
LOCATION CHECKLIST
• Accessibility, obstruction – Power
Steering reservoir is easily accessed.
Removal is open for about 360 degrees of
turn.
• Visibility – Power Steering reservoir is
clear and obvious.
SIMPLIFICATION CHECKLIST
Labeling – The reservoir cap has clear,
colored labeling.
Labeling – There is no label on the
reservoir itself. Also, there seems to be no
indication as to the correct fluid level, only
a warning not to go past it.
DESIGN FOR REPAIR CHECKLIST
Service aids – The cap is tethered to the
bottle.
93
Design for Serviceability (DFS)
Coolant & Washer Fluids
LOCATION CHECKLIST
• Obstruction – The reservoirs have
obstructions around them that interfere with
fluid pour. They are also located towards the
center of the vehicle.
• Visibility – The labeling and color of the
reservoirs make them distinctive given the
color of the surrounding parts.
SIMPLIFICATION CHECKLIST
• Labeling – The labeling of the reservoir
caps are clear and colored.
94
Design for Serviceability (DFS)
Coolant & Washer Fluids
(continued)
SIMPLIFICATION CHECKLIST
•Clustering – The two reservoirs are located
next to each other, have a similar appearance
but contain incompatible fluids.
•Labeling – The color and shape similarity of
the reservoirs make them indistinctive with the
caps removed. The bottles should have labels.
95
Design for Serviceability (DFS)
Air Cleaner
SIMPLIFICATION CHECKLIST
• Clustering – All of the elements for
servicing the air system are grouped
together.
• Labeling – There are no clear labels
for any components function.
96
Design for Serviceability (DFS)
Air Cleaner
(continued)
LOCATION CHECKLIST
•Accessibility – Assembly
attachments are located deep into
the vehicle cavity.
•Obstruction – The walls of the
compartment and the assembly
itself acts as obstructions for
servicing.
•Visibility – There are no colored
indications for attachment location
and they are located where there is
poor light under normal conditions.
97
Design for Serviceability (DFS)
Air Cleaner
(continued)
DESIGN FOR REPAIR
CHECKLIST
•Ergonomics – Separate,
manual fasteners are reduced
by slot and tab assembly
•Safety – If manual
manipulation is required, the
assembly is located quite
close to sheet metal which
may have sharp edges and
burrs.
98
Design for Serviceability (DFS)
Air Cleaner
(continued)
LOCATION CHECKLIST
• Accessibility, obstruction – the
cover is limited in its travel so it is
difficult to access the filter itself
for removal.
99
Serviceability of Cyclone Grinder
• Reducing the part count
makes the product easier to
service because the tool can
be assembled more quickly
and the user does not have
to keep many parts in
inventory for when a grinder
needs repair.
• Designing parts that can only
be assembled in the correct
positions and combining
small parts into subassemblies facilitates tool
maintenance assembly in
the plant.
http://bits.me.berkeley.edu/mmcs/cyclone/design4service.html
100
Serviceability of Washer
• Complete front
removes for easier
serviceability.
• Overall reduction of
parts.
http://www.warehouseappliance.com/staber.htm
101
Design for Serviceability
Aircraft Engines
• Removal of an Aircraft
Engine Starter with
Human Motion
• This shows the removal
path of a high
maintenance starter.
• This also shows:
– Design for Ergonomics
– Design for Assembly
http://www.crd.ge.com/esl/cgsp/projects/video/mech/service.html
102
Design for Serviceability
Aircraft Engines
• Removal Path of an
Aircraft Engine Sensor
• Film clip shows the
access path needed to
remove engine sensor.
• This also shows:
– Design for Assembly
– Design for Packaging
http://www.crd.ge.com/esl/cgsp/projects/video/mech/service.html
103
Design for Serviceability
Automotive
• Maintenance Access
Solid of a Car Shock
Absorber
• Film Clip shows access
path and clearance to
remove shock absorber.
• Methods also shows:
– Design for Assembly
– Design for Ergonomics
http://www.crd.ge.com/esl/cgsp/projects/video/mech/service.html
104
Design for Serviceability
Related X’s
• DFS is most inter-related to:
–
–
–
–
DFA (Assembly)
DFE (Environment)
DFE (Ergonomics)
DFR (Robustness)
105
Design for Serviceability (DFS)
Summary
Why - To stay competitive, a company must look at all
elements of customer satisfaction. To be profitable, a
company must consider the total product life cycle costs.
One of the elements that must be considered to accomplish
these goals is serviceability.
When - 70% of the life cycle costs of a product are committed
by the time of concept formulation. A company must
incorporate serviceability early in their designs to deliver a
product that is efficiently serviceable.
How - By following a step-by-step methodology, a company
can ensure that it has analyzed the opportunities and best
design directions for serviceability incorporation. By using a
simple checklists, the basic design features that lead to
more serviceable designs may be incorporated.
106
Design for Serviceability (DFS)
Summary
The Basic Methodology
•
•
•
•
•
Determine Initial Requirement
Determine Data Qualifiers
Investigate Product Serviceability
Investigate Opportunities
Integrate Results into the New Design
Design Elements
•
•
•
•
•
Location
Simplification
Standardization
Design for Repair
Life Factors
• Diagnostics
107
Design for Serviceability (DFS)
Summary
DFS Guidelines
• Minimize the number of layers of components
• Design the components that are most likely to fail or
need servicing close to the assembly surface
• Develop a modular product structure
• Minimize the number of connections between
subassemblies
• Use standard components
• Minimize specialist labor
108
References
•
References noted within
109