Transcript of "Maintenance and material handling methods (1)"
SanamV S Srikar
MAS flight Boeing 737 left KLIA at 2:00 pm.
All two engines, hydraulic systems working.
2:22 pm explosion shook plane.
Number 2 engine torn apart, 2 separate hydraulic lines ceased
In spite of maintenance work, engine still failed.
Imagine having no maintenance system.
• What is maintenance?
• Why do we need maintenance?
• What are the costs of doing maintenance?
• What are the costs of not doing maintenance?
• What are the benefits of maintenance?
• How can maintenance increase profitability of
• All actions necessary for retaining an item, or restoring to
it, a serviceable condition, include servicing, repair,
modification, overhaul, inspection and condition
• Increase availability of a system
• Keep system’s equipment in working order
What Is Maintenance ?
• Attempt to maximize performance of production
equipment efficiently and regularly.
• Prevent breakdown or failures.
• Minimize production loss from failures.
• Increase reliability of the operating systems.
• To achieve product quality and customer satisfaction
through adjusted and serviced equipment
• Maximize useful life of equipment
• Keep equipment safe and prevent safety hazards
• Minimize frequency and severity of interruptions
• Maximize production capacity – through high
utilization of facility
Problems in Maintenance
• Lack of management attention to maintenance
• Little participation by accounting in analyzing and
• Difficulties in applying quantitative analysis
• Difficulties in obtaining time and cost estimates for
• Difficulties in measuring performance
Problems Exist DueTo
• Failure to develop written objectives and policy
• Inadequate budgetary control
• Inadequate control procedures for work order, service
• Infrequent use of standards
• To control maintenance work
• Absence of cost reports to aid maintenance planning
and control system
• Must be consistent with the goals of production
(cost, quality, delivery, safety)
• Must be comprehensive and include specific
• Cost to replace or repair
• Losses of output
• Delayed shipment
• Scrap and rework
• Maintenance may be classified into four categories:
• (some authors prefer three categories- scheduled and
preventive maintenances are merged)
• Corrective or Breakdown maintenance
• Scheduled maintenance
• Preventive maintenance
• Predictive (Condition-based) maintenance
Corrective or BreakdownMaintenance
• Corrective or Breakdown maintenance implies that
repairs are made after the equipment is failed and can
not perform its normal function anymore.
• Quite justified in small factories where:
– Down times are non-critical and repair costs are less than
other type of maintenance
– Financial justification for scheduling are not felt
Scheduled maintenance is a stitch-in-time procedure
and incorporates .
– repair and overhaul of equipments
If neglected can result in breakdown
Generally followed for:
– overhauling of machines
– changing of heavy equipment oils
– cleaning of water and other tanks etc.
• Principle – “Prevention is better than cure”
• Procedure - Stitch-in-time
– locates weak spots of machinery and equipments
– provides them periodic/scheduled inspections and
minor repairs to reduce the danger of unanticipated
• In predictive maintenance, machinery conditions are
periodically monitored and this enables the maintenance
crews to take timely actions, such as machine
adjustment, repair or overhaul.
• It makes use of human sense and other sensitive
instruments, such as
–audio gauge, vibration analyzer, amplitude meter,
pressure, temperature and resistance strain gauges
• Unusual sounds coming out of a rotating equipment
predicts a trouble
• An excessively hot electric cable predicts a trouble
• Simple hand touch can point out many unusual
equipment conditions and thus predicts a trouble
Long-Range (master) Schedule
• Covering a period of 3 months to 1 year.
• Based on existing maintenance work orders (blanket
work order, backlog, anticipated EM).
• Balancing long-term demand for maintenance work
with available resources.
• Spare parts and material could be identified and
ordered in advance.
• Revision and updating to reflect changes in the
plans and maintenance work.
• Covering 1 week.
• Generated from the master schedule.
• Takes into account current operations schedules and
• Allow 10% to 15% of the workforce to be available for
• The schedule prepared for the current week and the
following one in order to consider the available backlog.
• The work orders scheduled in this week are sequenced
based on priority.
• CPM and integer programming techniques can be used
to generate a schedule.
• Covering 1 day.
• Generated from weekly schedule.
• Prepared the day before.
• Interrupted to perform EM.
• Priorities are used to schedule the jobs.
Partnering with maintenance
Maintenance and Reliability
Clean and lubricate.
Monitor and adjust.
Make minor repair.
Keep computerized records.
Reputation for quality.
(Actual vs. standard)
with skills, wages,
with parts list
and work order
Optimal point (lowest
cost maintenance policy)
Full Cost View
Optimal point (lowest
cost maintenance policy)
Full cost of
How Maintenance is Performed
Increasing Operator Ownership Increasing Complexity
maintenance costs less and
is faster the more we move to the left
Competence is higher as we
move to the right
• Material Handling accounts for:
– 25% of all employees,
– 55% of all factory space,
– 87% of production time
– 15-70% of the total cost of a manufactured product
• 3-5% of all material handled becomes damaged
– “Totally eliminate mistakes”
– However, handling less is not the answer.
• Material handling is a means by which:
– Total manufacturing costs are reduced through
• Reduced inventory
• Improved safety
• Improved material control
• By reducing damage
– Manufacturing quality is improved by:
• By giving more time to manufacturing process
• Proper supervision of machinery will lower defects in
•Material handling is the art and science of moving, storing,
protecting, controlling and status of material
–Moving: is required to create time and place utility.The
value of having the material at the right time and the right
–Storing: Provides a buffer between operations, facilitates
the efficient use of people and machines.
–Protecting: Includes the packaging,damage and theft.
–Controlling: Physical storage, sequence and space
–Status: Real-time awareness of the location, amount,
destination and schedule of material.
Material Handling is the function of moving the right material
to the right place at the right time, in the right amount, in right
sequence, and in the right condition to minimize production
The cost of MH estimates 20-25% of total manufacturing
labor cost in the United States [The Material Handling
Industry of America (MHIA)]
• Raw materials:- This is material which is used in product
manufacturing and is in an unprocessed condition.(eg
• Purchased Parts:- These are the items used in the
assembly of the product.(eg processor)
• In-progress materials:- They are called ‘work in progress’
inventories. These goods require further processing.
Finished materials:- These are fully manufactured
goods, inspected and ready for delivery to the
Supplies:- These are consumable goods used in the
process of manufacturing.(eg electricity)
Principles of material handling
• Least handling is the best handling.
• Lengths and number of moves to be minimized.
• Unit load
• Minimize the distance.
• The design of the container. e.g. shippers are used for
storing finished bulk. & for raw materials as per the
property of materials they are stored- plastic
containers ( light weight containers)
• Re-handling and back tracking of the materials should
• The materials handling service should not interfere
with the production flow.
Six-step engineeringdesing process
1. Define the objectives and scope for the material handling
2. Analyze the requirements for moving, storing, protecting, and
3. Generate alternative designs for meeting material handling
4. Evaluate alternative material handling system designs.
5. Select the preferred design for moving, storing, protecting, and
6. Implement the preferred design, including the selection of
suppliers, training of personnel, installation, debug and startup
of equipment, and periodic audits of system performance.
Categories of Material Handling Equipment
1. Containers and Unitizing Equipment
2. Material Transport Equipment
• Industrial Vehicles
• Monorails, Hoists, and Cranes
3. Storage and Retrieval Equipment
• Unit Load Storage and Retrieval
• Unit Load Storage Equipment
• Unit Load Retrieval Equipment
• Small Load Storage and Retrieval
4. Automatic Data Collection and Communication Equipment
• Automatic Identification and Recognition
• Automatic Paperless Communication
Study the system relationships thoroughly prior to preliminary planning in order to identify
existing methods and problems, and physical and economic constraints, and to establish
future requirements and goals.
Establish a plan to include basic requirements, desirable options, and the consideration of
contingencies for all material handling and storage activities.
Integrate those handling and storage which are economically viable into a coordinated
system of operation including receiving, storage, production, assembly, packaging,
warehousing, shipping, and transportation.
Handling product in as large a unit load as practical.
Readily have access to the knowledge, expertise, professionalism, and industry leadership.
Standardize handling methods and equipment wherever possible.
Make effective utilization of all cubic space.
Recognize human capabilities and limitations by designing material handling equipment and
procedures for effective interaction with the people using the system.
Include energy consumption of the material handling systems and material handling
procedures when making comparisons or preparing economic justifications
Minimize adverse effects on the environment when selecting material handling equipment
Use methods and equipment which can perform a variety of tasks under a variety of
Mechanize the handling process where feasible to increase efficiency and economy in the
handling of materials.
Simplify handling by eliminating, reducing, or combining unnecessary movements and/or
Utilize gravity to move material wherever possible, while respecting limitations concerning
safety, product damage, and loss.
Provide safe material handling equipment and methods which follow existing safety codes
and regulations in addition to accrued experience.
Prepare an operational sequence and equipment layout for all viable systems solutions, then
select the alternative system which best integrates efficiency and effectiveness.
Consider computerization in material handling and storage systems when circumstances
warrant for improved material and information control.
Compare the economic justification of alternative solutions in equipment and methods on
the basis of economic effectiveness as measured by expense per unit handled.
Prepare a plan for preventive maintenance and scheduled repairs on all material handling
Provide reliable and dependable material handling equipment from manufacturers who have
demonstrated quality and longevity in the industry
Maintenance and Material handling helps in Improving
efficiency of a production system by ensuring the right
quantity of materials delivered at the right place at the right
time via best economic way and it helps in cut down indirect
labor cost, reduces damage of machine and material during
production , storage and movement and maximizes space
Material handling and maintenance is a scientific approach of
reducing the cost of production and is necessary for all
industries , however it should be implemented only after
thorough analysis of cost , available resources and budgetary