Maintenance And Material Handling MethodsBy-

Sanam V S SrikarHarpreet Singh Grover

MAINTENANCE

IMAGINE:

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 to work.

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

company?

QUESTION?

• All actions necessary for retaining an item, or restoring to it, a serviceable condition, include servicing, repair, modification, overhaul, inspection and condition verification

• Increase availability of a system• Keep system’s equipment in working order

What Is Maintenance ?

Purpose of 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.

Principle Objectives in Maintenance

• 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 reporting costs• Difficulties in applying quantitative analysis• Difficulties in obtaining time and cost estimates

for maintenance works• Difficulties in measuring performance

Problems Exist Due To

• Failure to develop written objectives and policy• Inadequate budgetary control• Inadequate control procedures for work order,

service requests etc.• Infrequent use of standards• To control maintenance work• Absence of cost reports to aid maintenance

planning and control system

Maintenance Objectives

• Must be consistent with the goals of production (cost, quality, delivery, safety)

• Must be comprehensive and include specific responsibilities

Maintenance Costs

• Cost to replace or repair• Losses of output• Delayed shipment• Scrap and rework

Types of Maintenance

• 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 Breakdown Maintenance

• 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

Scheduled maintenance is a stitch-in-time procedure and incorporates .– inspection – lubrication – 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.

Preventive Maintenance (PM)

• Principle – “Prevention is better than cure”• Procedure - Stitch-in-time • It– locates weak spots of machinery and equipments – provides them periodic/scheduled inspections and minor repairs to reduce the danger of unanticipated breakdowns

Predictive (Condition-based) Maintenance

• 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 etc.

Predictive Maintenance (Contd.)

• 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

Maintenance (Depend on The Time Horizon)

1. Long-range (master) schedule

2. Weekly schedule

3. Daily schedule

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.

Weekly Schedule

• Covering 1 week.• Generated from the master schedule. • Takes into account current operations schedules

and economic considerations.• Allow 10% to 15% of the workforce to be

available for emergency work.• 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.

Daily Schedule

• Covering 1 day.• Generated from weekly schedule.• Prepared the day before.• Interrupted to perform EM.• Priorities are used to schedule the jobs.

Maintenance ManagementEmployee Involvement

Partnering with maintenance Personnel.Skill training.Employee empowerment.

Maintenance and Reliability Procedures

Clean and lubricate.Monitor and adjust.Make minor repair.Keep computerized records.

ResultsReduced inventory.Improved quality.Improved capacity.Reputation for quality.Continuous improvement.Reduced variability.

Computerized Maintenance System

Output Reports

Inventory and purchasing reports

Equipment parts list

Equipment history reports

Cost analysis (Actual vs. standard)

Work orders– Preventive

maintenance– Scheduled

downtime– Emergency

maintenance

Data Files

Personnel data with skills, wages,

etc.

Equipment file with parts list

Maintenanceand work order

schedule

Inventory of spare parts

Repair history file

Maintenance Costs

Total costs

Breakdown maintenance costs

Cost

s

Maintenance commitment

Traditional View

Preventive maintenance costs

Optimal point (lowestcost maintenance policy)

Maintenance Costs

Cost

s

Maintenance commitment

Full Cost View

Optimal point (lowestcost maintenance policy)

Total costs

Full cost of breakdowns

Preventive maintenance costs

How Maintenance is Performed

Operator(autonomous maintenance)

Maintenance department

Manufacturer’s field service

Depot service(return equipment)

Increasing Operator Ownership Increasing Complexity

Preventive maintenance costs less and is faster the more we move to the left

Competence is higher as we move to the right

Material Handling

Towards a definiton

• 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.

Motivations

• 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 products.

Definitions:

•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 place.–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 between material.–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 cost.

The cost of MH estimates 20-25% of total manufacturing labor cost in the United States [The Material Handling Industry of America (MHIA)]

Classes of materials

• Raw materials:- This is material which is used in product manufacturing and is in an unprocessed condition.(eg cotton)

• 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 customers.

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 be avoided.

• The materials handling service should not interfere with the production flow.

Example of Materials and People Flow

Six-step engineering desing process

1. Define the objectives and scope for the material handling system.

2. Analyze the requirements for moving, storing, protecting, and controlling material.

3. Generate alternative designs for meeting material handling system requirements.

4. Evaluate alternative material handling system designs.5. Select the preferred design for moving, storing,

protecting, and controlling material.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• Containers• Unitizers

2. Material Transport Equipment• Conveyors• 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

Containers

Unitizers

Conveyors

Industrial Vehicles

Storage and Retrieval

Monorails, Hoists and Cranes

20 Principles Of Material Handling

ORIENTATION PRINCIPLE: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.

PLANNING PRINCIPLE:Establish a plan to include basic requirements, desirable options, and the consideration of contingencies for all material handling and storage activities.

SYSTEMS PRINCIPLE: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.

UNIT LOAD PRINCIPLE:Handling product in as large a unit load as practical.

ACCESSIBILITY PRINCIPLE:Readily have access to the knowledge, expertise, professionalism, and industry leadership.

STANDARDIZATION PRINCIPLE:Standardize handling methods and equipment wherever possible.

SPACE UTILIZATION PRINCIPLE:Make effective utilization of all cubic space.

ERGONOMIC PRINCIPLE:Recognize human capabilities and limitations by designing material handling equipment and procedures for effective interaction with the people using the system.

ENERGY PRINCIPLE:Include energy consumption of the material handling systems and material handling procedures when making comparisons or preparing economic justifications

ENVIRONMENTAL PRINCIPLE:Minimize adverse effects on the environment when selecting material handling equipment and procedures.

FLEXIBILITY PRINCIPLE:Use methods and equipment which can perform a variety of tasks under a variety of operating conditions.

MECHANIZATION PRINCIPLE:Mechanize the handling process where feasible to increase efficiency and economy in the handling of materials.

SIMPLIFICATION PRINCIPLE:Simplify handling by eliminating, reducing, or combining unnecessary movements and/or equipment

GRAVITY PRINCIPLE:Utilize gravity to move material wherever possible, while respecting limitations concerning safety, product damage, and loss.

SAFETY PRINCIPLE:Provide safe material handling equipment and methods which follow existing safety codes and regulations in addition to accrued experience.

LAYOUT PRINCIPLE:Prepare an operational sequence and equipment layout for all viable systems solutions, then select the alternative system which best integrates efficiency and effectiveness.

COMPUTERIZATION PRINCIPLE:Consider computerization in material handling and storage systems when circumstances warrant for improved material and information control.

COST PRINCIPLE:Compare the economic justification of alternative solutions in equipment and methods on the basis of economic effectiveness as measured by expense per unit handled.

MAINTENANCE PRINCIPLE:Prepare a plan for preventive maintenance and scheduled repairs on all material handling equipment

RELIABILITY PRINCIPLE:Provide reliable and dependable material handling equipment from manufacturers who have demonstrated quality and longevity in the industry

Conclusion

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 utilization.

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 constraints.

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