Identification, causes, consequences, and elimination of wastes
Wastes are unnecessary actions, processes, materials, time, or premises, not increasing the value of products and customer satisfaction.
Lean production distinguishes seven types of wastes:
1. Overproduction wastes:
1. Production of products that are not needed, in excess Number.
2. Untimely production of products.
Reasons occurrence of wastes caused by overproduction:
- Issue products in large batches.
- Issue products in advance in the absence of demand.
- Impossibility quick readjustment.
- Creation a large amount of inventory to replace defective products.
- Simple equipment and the desire to load it.
- Infringement of technological discipline.
Consequence wastes from overproduction:
- Preliminary procurement of materials and parts.
- Intermittent the nature of the production flow (irregularity).
- Redundancy Stocks.
- Absence flexible planning.
- Appearance Defects.
How Avoid overproduction wastes:
- Abridge time for reconfiguration of equipment.
- Flatten loading of the production line.
- Ensure balance between production capacity and load.
- Observe technological discipline.
- Inculcate pulling system using Kanbans.
2. Stocks – any excess inflow of products into the production a process, whether it is a raw material, a semi-finished product or a finished product.
Reasons wastes caused by excess stocks:
- Issue products in large batches.
- Management pressure production.
- Invalid setting a goal – “machines should work workers should not stand idle”.
- Unreliable deliveries and quality problems of external and internal suppliers.
- Trouble related to long-term readjustment.
- Intermittent the nature of the production flow.
- Proactive production.
- Issue defective products (additives to the plan for technologically inevitable defects).
- Too fast production rate on the previous process compared to the subsequent one.
Consequences Wastes from excess stocks:
– freezing working capital.
– Requires additional places for storage.
– risk spoilage and obsolescence of the product.
– Requires additional human resources for the organization of control over safety.
How Avoid excess stocks:
– define product turnover period.
– adjust production flow.
– arrange the equipment according to the sequence of execution Processes.
– apply pulling system using Kanbans.
– produce products only on time and only in the quantity that it is necessary.
– abridge time for equipment readjustment.
3. Over-processing – an effort that does not add value to the product/service from the consumer’s point of view.
Causes of wastes, caused by unnecessary processes and operations:
– Inaccurate identification of consumer needs.
– lack of standard operation and changes in the types of products produced.
– Insufficient pre-treatment of materials.
– Technological Defects.
– Insufficient knowledge of the technological process.
– infringement technological discipline.
Consequences of wastes from over-processing:
– Delay Production.
– increase the possibility of defects.
– absence added value for the consumer.
– surcharge materials, tools, human resources, etc.
How Avoid unnecessary processing:
– define together with the consumer, the value of the produced ghoode.
– perfect product design and manufacturing technology
– Products.
– develop rationalization and inventive activity.
– develop clear standards.
4. Unnecessary movements – any movement of people, tools or equipment that does not add value to the final product or service.
Reasons the appearance of wastes caused by unnecessary movements: – inefficient methods of performing work.
– Inconsistent Operation.
– lack qualifications of the worker.
– absence workers have the right skills.
– Big workload per worker.
– absence experience in applying standard operations in practice.
– irrational (without taking into account ergonomics) organization of the workplace.
Consequences of wastes from excess Movements:
– Low labor productivity.
– Increased fatigue of the employee.
– loss production cycle.
How to avoid unnecessary movements:
– organize a workplace using the tool of the 5C system.
– perfect technological process of manufacturing the product.
– equip workplace with the application of ergonomic principles.
– place equipment on the site, taking into account the technological cycle.
– raise qualifications of workers.
– teach working standard operations.
– standardize Work.
5. Defects and mistakes – products requiring inspection, sorting, disposal, downgrading, replacement or repair
Reasons the appearance of wastes caused by defective products and defects:
– low the level of qualification of the performers.
– imperfection technology and technologically inevitable defects.
– lack standard work, lack of skills.
– Inefficient quality control and defect analysis.
– incoordination between the consumer and the supplier.
– Inappropriate quality of supplied products.
– Design and technological errors.
Consequences wastes caused by defective products and defects:
– dissatisfaction Consumer.
– Excess resource consumption.
– reduction prestige of the enterprise and its competitiveness.
How avoid defects and defects:
– raise qualification of performers.
– standardize work.
– Apply the Method of Poke – Yoke.
– improve the quality of control operations.
– determine, together with the consumer, the value of the products.
– improve the methods of incoming control.
– improve design and technology
6. Waiting – interruptions in work associated with the expectation of people, materials, equipment or information.
Reasons the appearance of wastes caused by waiting:
– production in large batches.
– high time spent on readjustment and repair.
– breaks in the production flow.
– insufficient power of the equipment.
– uncoordinated flow of goods and materials.
– additional time caused by other types of loss.
– inflexible operating time.
– insufficient number of workers in the required profession.
– irrational location of equipment.
– inefficient technological preparation of production.
Consequence of wastes caused by expectation:
– increase in the production cycle:
– untimely satisfaction of consumer expectations.
– exceeding the standards for work in progress.
– an emergency method of work to catch up and, as a result, increasing the possibility of defect or defect, increasing the level of Injury.
How Avoid wastes caused by waiting:
– improve the planning system.
– master quick readjustment.
– arrange the equipment in accordance with the technological cycle.
– Implement the Rock Method – Yoke.
– improve in-line production.
– implementation of multi-machine maintenance.
– development of additional professions by workers.
– modernization of the machine park.
– identification of bottlenecks and organization of additional jobs.
7. Transportation – excessive transportation of parts or materials within the enterprise.
Reasons the appearance of wastes caused by excessive transportation:
– production of products in large batches with intermediate storage.
– irrational technological preparation of production.
– Insufficient the number of employees of the required profession.
– Unauthorized automation of the production process.
– Irrational location of equipment and sites.
– absence continuous flow.
– not value-adding operations.
– standard way of thinking.
Consequences Wastes caused by excessive transportation:
– Added time and space is taken.
– Can an additional means of transportation is required.
– Increases risk of damage to products during loading and unloading.
– may require further agreement on the issue of transportation with subdivisions.
How avoid unnecessary transportation wastes:
– create maps of vehicle routes.
– Rational organization of the workplace.
– teaching workers in additional professions.
– optimize technological routes.
– reduce inventories.
– perfect technological preparation of production (manufacture of devices, excluding transportation as an operation).
– perfect in-line production.
– arrange equipment on the site, taking into account the technological cycle of manufacturing the product.
– promotion vehicle load factor.
– Standardize transport procedures.