Introduction
Product quality determines the success with the product. One of the key drivers of quality is the performance of the product over a period of time. Performance of product is determined by the reliability and redundancy. Reliability increases the efficiency while redundancy increases the current capability and expectations.
Any production organization sets a goal of achieving production efficiency and ability to operate at an optimum level at all the time. Furthermore, the production should be achieved with a least level of wastage.
Production reliability is dependent upon speed, quality and time availability. Equipment failure leads to outage and frequent breakdown, which affect the quality of the products. Frequent machine breakdowns also decrease production speed thus affecting time availability. Theoretically, it is recommended to set employees with a goal of reliability.
Reliability
Important characteristics of reliability are as follows:
- Reliability: This highlights performance of product or system within a known set of parameters.
- Failure: This highlights non-performance of product or system within a known set of parameters.
- Normal Operating Conditions: These are conditions, which let the system or product performs to the optimum level without stress.
- Reliability Leads to Profitability: This highlights that consistent reliability exhibited by product or system leads to increase in profit for an organization.
Reliability is divided into two main parts, and they are as follows:
- Inherent Reliability: This is kind of reliability, with which product is sold.
- Achieved Reliability: This kind of reliability is observed during the daily usage of the product.
It has been observed that reliability increases if regular maintenance is undertaken.
Redundancy
Redundancy is defined as an addition of information, resource and time to the existing product or system than required for its optimum performance. Redundancy is of following types:
- Resource Redundancy: Resource redundancy is made up of two parts; software redundancy and hardware redundancy. Software redundancy talks about addition of software in form of program or patch to undertake a task of fault detection. Hardware redundancy talks about addition of hardware for identifying or modifying defects.
- Information Redundancy: As the same suggest information redundancies provide extra information to implement given function of error detection.
- Time Redundancy: As the same suggest time redundancies provide additional time to fault detection.
From the above it can be concluded that redundancy provides extra reliability to product and systems. It helps prevention of decline in performance without direct manual intervention. The importance of the redundancy increase even more when system or product is performing a critical, sensitive and complicated task.
Redundancy is sometimes accompanied with failure. These failures are function failure and reliability failure. Functional failure is observed from the start of product life, and it is caused by production or raw material defect. Reliability failure is observed after usage over period of time.
Reliability is measured through reliability index and failure rate. Reliability index is defined as the ratio of production losses to the loss per production loss. Failure rate is defined as the number of failure per unit time, which decreases initially with passage of time.
Redundancy and Total Quality Management
Total quality management philosophy talks about producing consistent quality of product over a period of time. Redundancy production increases overall cost of production as the extra effort is put into maintaining targeted quality.
