practice of design for maintenance -...
TRANSCRIPT
Practices of Design for
Maintainability
• Design - transformation of idea into process that meets designer’s
requirements & end user’s needs
• Maintainability - degree to which design maintained economically &
efficiently - characteristic of final design; maintenance - result of design
• Design for Maintainability - design plant to find optimum balance
between capital cost & maintenance cost
• For designer, end users both O&M teams of plant
• Survey conducted with 5 concentrator engineers within Lonmin
Platinum
• What would be requirements in terms of plant maintainability when
designing new concentrator?
Practices of Design & Maintainability
• Top 4 requirements:
Ease of access,
Standardization of eqpt internally & between concentrators,
Skill levels to maintain eqpt &
Redundancy of running eqpt, all have time to repair
component
• Easier to access eqpt, shorter time to maintain
• Eqpt standardized, specialized skills not required, reducing time
to repair
• Focus on time to repair (or MDT), plot of ‘MDT’ vs ‘MTBM’ for
various operational availability levels
• At 90% availability, plant engineers 80 hours to complete all
corrective/preventative actions on plant; down time includes all
delays, not only pure repair time of eqpt
Practices of Design & Maintainability
• Design team reduce MDT when eqpt fails, Some practical
examples include:
Provide lifting eqpt access to all high maintenance eqpt, e.g.
pumps & pulleys
Install permanent trolleys on all crawl beams to increase time
to repair
Install standby pumps & dedicated pipelines (with auto
changeover), not affecting available maintenance hours per
month
Make pumps accessible under flooded plant conditions,
through walkways & access platforms
Provide dedicated pipe routes with access
Install split guards & split bearings on main conveyor pulleys
Provide easy & clean access to all instrumentation
Take cognizance of environmental implications of oil spills +
time to clean up
Practices of Design & Maintainability
• Maintainability: design parameter; not expensive if considered early in
design
• Failure to consider maintenance team very expensive in form of safety
risks to personnel, eqpt retrofits, operation disruptions & cutting torch
maintenance
• Design engineer review project goals & strategies with operational team
prior to design sign-off; invest time to compile design & installation
specifications & sign-off from operational teams & contractor for design
& construction
• During design, utilize 3D design packages, specifically review
maintenance access with key maintenance team
• Design improvements apparent during construction; flexible during
construction & get maintenance team on site early
• Cheaper to improve design during construction, than disrupting value
chain of running item
Practices of Design & Maintainability
• Survey conducted of largest 211 building design firms in USA -
investigate relationship between design practices & maintenance
• Findings shed light on extent to which maintenance issues considered
when designers specify building materials & service eqpt; level of
designers' knowledge in maintenance-related issues; degree to which
design personnel exposed to training in maintenance-related matters;
extent to which designers consult property managers/maintenance
consultants; relative importance of maintenance issues to other design
factors; level of difficulty in cleaning, inspecting, repairing, replacing
various components; magnitude & frequency of complaints that
designers receive from clients/tenants
• Building Performance enhanced if designers cognizant of maintenance-
matters
• Whether planning to construct new facility or remodel existing one,
process begins with understanding of needs, space, shop eqpt & layout,
bays, maintenance, parts rooms, utility requirements, etc.
Early Planning
• Eqpt selection, layout, utility requirements & finishes considered
early in process, earlier in design process needs identified,
more likely approved & less cost
• After construction, additions require expensive change order
• During construction, same line cost $1,000 to add as change
order
• Planning & attention to smallest detail prevent mistakes that
hinder efficiency of maintenance facility
• Lighting – Choose light fixtures offer full spectrum of light
• Lighting ramifications on efficiency, functionality & safety of
facility + on atmosphere of workplace
• High-pressure sodium lights work well outdoors; not suited for
maintenance shop
Early Planning
• Inside building, lights’ orange-yellow cast creates poor color
rendition, different colored wires look same & blood
indistinguishable from grease
• Overhead Clearance – Ductwork, plumbing, cranes installed too
low encroach on overhead space & interfere with unobstructed
vertical clearance in repair bay, rendering cranes & lifts useless
• Door Size: Measure each vehicle‘s width & height – mirrors &
vertical extensions; 10’ wide garage doors accommodate truck 8’
wide
• Most trucks mirrors protrude up to 1’ on each side, which shrinks
clearance from 2‘to only few inches
• Building Finishes/Aesthetics: bottom 4’to 6’ of shop walls durable
(concrete or masonry) to withstand abuse in shop environment.
• Entire inside of building walls/structure painted to allow building
maintenance to extend useful life of facility
• Design facility's exterior to complement surrounding environment
& adding native landscaping help gain public approval of project
Early Planning
• Expandability – building not only handles current work load,
adaptable & accommodate demands 20 years from now
• Additional bays not built during initial construction, room left on
site to accommodate expansion
• Load bearing walls avoided to maximize flexibility for future
odifications
• Public Involvement – Everyone with interest in project informed
• Appearance – Form follows function, make functional building
good-looking; isn't possible to make good-looking building
functional
• Peer Review: During initial design, encourages shop, fleet & fleet
maintenance managers to hold peer review session, invite other
managers to critique design. Peers contribute great ideas &
validate design
• Design maintenance facility: Ask right questions & planning in
advance means maintenance managers experience smooth
design & construction process that results in safe, efficient,
positive work environment lasting whole life of facility
Impact of Technology on FM
• FMs asked to install, implement, work with variety of technologies
without any prior experience in information technology
• Technologies covered include:
Building information modeling (BIM)
Building automation systems (BAS)
FM automation (CAFM/IWMS)
Condition assessment/life cycle analysis
Radio frequency identification (RFID)
Geographic information systems (GIS)
Social networking
Sustainability and energy analysis
Information and communications technology (ICT)
Workflow technology that supports standards - Business Process
Modeling Notation (BPMN) & those developed by Workflow
Management Coalition (WfMC)
Support/Logistics
Products
Development
Design Influence
System Reliability Analysis, Modeling, and Allocation
Fault Tree Analysis (FTA)
Maintainability Analysis
Level of Repair
Maintainability Prediction
Design Reviews and Evaluation
Failure Mode, Effects, and Criticality Analysis (FMECA)
System Redesign/ Improvement
Reliability Centered Maintenance (RCM)
Maintenance Task Analysis (MTA)
Have Requirements Been Met? Support Test/ Evaluation
Reliability Prediction
System Test & Evaluation (Hot Bed Testing)
Sustaining
SYSTEM
Support
Functional Analysis
Functional Flow/ Data Flow Diagrams
Allocation of System Requirements
System Architecture/ Selection of System Elements
Concept of Operations
TLR & Maintenance Concept
Yes
No
Detailed Support Product List
Cost as an Independent Variable (CAIV): Design to Affordability Analysis (Strategic Decision Making)
Technology/Standards Evolution & COTS Products Market Surveillance
Technology Refreshment
• Supply Support (Spare/Repair Parts)
• Maintenance Planning
• Test/Support Equipment
• Technical Documentation/IETM
• Manpower/Personnel
• Training/CBT
• Facilities; PHS&T
• Design Interface; Computing
Support
Elements of Logistics Support:
Requirements For The:
Evaluation Tech. Refreshment Fleet Feedback
Lifetime Support
Systems & Supportability Engineering
Packaging, Handling, Storage, and Transportation (PHS&T) is the combination of resources, processes, procedures, design, considerations, and methods to
ensure that all system equipment, and support items are preserved, packaged, handled, and transported properly, including environmental considerations, &
..
Characteristics Of Maintainability
• Users left out from design stage
• Builder not notified of original concept or design intent
• Designers chose special fitting/eqpt difficult to maintain • Operational availability issues • Excellent operational maintainability:
Why Buildings Fail
• As facilities completed, owner's maintenance responsibilities increase. (need for
maintenance services increases with addition of new buildings, for many
government agencies, manpower & budgets frozen or reduced) It is not the
responsibility of architect/designer to maintain facility, this aspect not fully
considered during design process
• When decisions made regarding design without maintenance, ==> facility more
costly to maintain, or components cannot be maintained:
Ceiling lights installed only accessed & changed out with scaffolding,
requiring closure of entrance to facility for a week
Air-conditioning unit installed above drop ceiling in restroom or office area
with no room for ladder set up. Unit accessed by technician if stands on
restroom or office partition; unit will not be properly maintained & relocated
Lights installed in new buildings not accessible; abandoned when lamps fail
Lights requiring access panel to be cut into existing walls to access ballasts
High-cost, custom lighting fixtures/lamps installed in parking garages. As
they fail, replaced with lower-cost fixtures
Why Buildings Fail
• Rooftop air-conditioning units with no elevator access to bring
chemicals to units; A technician must carry chemicals up to equipment
• Trees planted very close to new buildings; results in clogged
downspouts during rainy season & lead to premature roofing failure
• Lack of enough telephone outlets, electrical outlets, computer
outlets/cables. It is far less expensive to install extra eqpt when building
being built than to add t after building is in service. This leads to
exposed wiring, holes in finishes, other degradations of building's
aesthetics
• Installing inferior-quality components to save up-front money. Carpet-
small initial cost increase, long-term cost reduced dramatically. Carpets
installed with 20- to 25-year non-prorated warranties
• Installing large glass architectural structure in front of new building,
requires purchase of $1 million piece of eqpt to facilitate cleaning glass
• Installing exterior "uplights", inherently fail due to moisture getting into
fixtures
Why Buildings Fail
•Eqpt installed easily during construction inaccessible after final walls &
other appurtenances completed
•Installation of high-maintenance security systems
•High-maintenance eqpt installed with no local vendor support
•What can be done to make facilities more maintainable, less
costly to operate during building life?
Consider following:
• Dialogue between engineers, architects, designers, customers,
maintenance personnel, contractors. Dialogue must start at first
meeting & carry throughout project
• Architectural or engineering firm uses staff for quality control or
contractor for constructability review, in-house maintenance group
considered resource for design review
• Troughout design process - maintenance standards for organization
Why Buildings Fail
• Close interaction throughout design & construction phases,
e,g, input to & review of design by maintenance personnel.
Assign knowledgeable maintenance professional part of design
& build team, reduce routine burden
• Adequate time allowed for document review. Maintenance
need to assert importance of their input to organization &
schedule adequate time
• Being involved from 1st meeting on, maintenance staff avoid
last- minute reviews vs in-depth reviews
• Consider maintenance requirements to keep it that way
Maintainability Strategy
• High system availability & reliability
• Align w/service partners; LCCM
• Sustainability of built environ (Green Mark or equivalent)
• DfM & operation
• Corrective, preventive, predictive maintenance
• CAFM & related ICT
• Take over audit/hand-back
EXAMPLE
• FP system poorly maintained higher average failure rate than same system maintained w/dedicated program, periodically
• Checklist & forms – Maintainity
based
• Predictable, specifiable,
measurable parameters
Specification design; Fault
detection
Isolation, built-in test, auto test
eqpt, Comms for periodic
exercise/monitoring of FP eqpt
• FMEA Criticality Analysis
• M&E Reliability Stress Analysis
• Quality Assurance & Reliability,
inclusion in specs/contract for
procurement of critical FPS
DfM Checklist
Checklist categories:
• General Maintenance Reduction
• Safety & Environmental System Design Features
• Design Standardization Features
• Design Features for Routine Maintenance
• Design Features for Troubleshooting
• Design Features for Repair/Replacement
• Visual Inspections & Accessibility
• Design for Physical Accessibility
• M&E System maintenance Design
• Personal Protective Equipment
• Storage Battery etc.
• DfM: product serviceable (easily repaired) & supportable (cost-effectively kept in or restored to usable condition)
• Durability (absence of failures)
• Reliability- how long eqpt down/available
Design Out For Maintenance
• DoM conflicting: design-out maintenance problems, no maintenance • DoM root cause elimination category where solution to DfR & intentionally create
high reliability eqpt through engineering design change to components • Design engineer considers plant improvement as proactive activity for cost
reduction. Particularly DoM for failure elimination
• Many organizations adopted unattainable goal of ‘All accidents preventable. Goal helps people focus on ways to prevent accidents, i.e. reducing unsafe conditions/unsafe acts
• Eqpt failures in plant. Focusing on goal e.g. ‘all failures preventable’, or ‘all downtime preventable’, leads plant personnel to identify causes of failures & discover ways to reduce them
• DoM - Maintenance tactic whereby changes or modifications done to eqpt to remove failure cause, allow other maintenance strategies applicable in managing consequence
• To manage consequences of failure & allow failure in better-managed, less-costly fashion- change in maintenance &/or operating strategy to those actions that deliver lower maintenance costs
• Change maintenance practizes to reduce stress in eqpt components, increase time to a component’s failure - not DoM causes of failure
• DOM: elimination of maintenance through creation of reliability by design
Design Out For Maintenance
• In Reliability Centered Maintenance (RCM), final solution when maintenance &/or operating strategy ineffective in reducing risk
Design-out & Design for Reliability (DfR)
• Proactive reliability-creating, include: Failure Mode Effects Analysis FMEA, Physics of Failure Analysis PoFA, Highly Accelerated Life Testing HALT, Highly Accelerated Stress Screening HASS, etc.
• Remove failure through component design changes
• In design prototype & make it fail, looking for failure modes to DoM
• Finite Element Analysis FEA to ‘virtually prototype’ component designs
• Before making part, model digitally & apply computer-generated stresses to simulate what might happen & component’s weaknesses
• Make real component & put it in real machine, stress it through failure testing trials to identify failure modes
Design-out & Risk Reduction
• Economic value from better design. Make changes to design because less costly
• Operating risk drives need for design change
• With DfR improvement, better engineered designs; high reliability components
• DfR powerful methodology for defect removal & failure cause elimination so maintenance not required
FIRE PUMP/TANK ROOM +
CONSUMER ELECT S/R – STORES
HT S/R – HT CABLE
• High tension cables
in HT Switch room
laid on ground and
exposed, pose as
safety hazard
Thank You !!