Quality Control Techniques

Introduction

Quality of product and services determines success or failure of the organization. Consumers expect the company to maintain high-level of quality and consider it an important aspect of satisfaction.

Quality management, therefore, becomes very important as far as any organization is concerned.

Quality management can be accomplished through various quality control techniques. Quality assurance and quality control are objective oriented and can be achieved through statistical quality control.

Statistical quality control requires usage of acceptance sampling and process control techniques. Statistical quality control extensively uses chart to measure the acceptance level of the product samples.

Objective is to ensure that products fall within pre-decided upper control and lower control limits. Any sample falling outside the limits is inspected further for corrective action.

Quality Control

The quality of product or service is ensuring if proper designing process is followed. This designing process needs to be backed by appropriate process design supported by a suitable technology which confirms to requirements of customers.

Quality control ensures that defects and errors are prevented and finally removed from the process or product. Therefore, quality control should include; planning, designing, implementation, gaps identification and improvisation.

If organization can implement a stringent quality control than following benefits are possible:

• Reducing product defects lead to less variable cost associated with labor and material.
• Reduction in wastage, scrap and pollution.
• Ability to produce quality products over longer period of time
• With quality maintenance needs for inspection reduces leading to decrease in maintenance cost
• Large pool of satisfied customers.
• Increase in employee motivation and awareness of quality.
• Increase in productivity and overall efficiency.

Above mentioned points are relevant not only for production stage but are equally important for input material, manufacturing process, delivery process, etc.

Statistical Quality Control

Quality control techniques require extensive usage of statistical methods. The advantages of the statistical analysis are as follows:

• Statistical Tools are automated and therefore, require less manual intervention, leading cost reduction
• Statistical tools work on a model thus are very useful where testing requires destruction of products.

Statistical Quality tools can broadly be classified into following categories:

• Acceptance sampling is an important part of quality control wherein quality of products is assessed post production.
• Statistical process control helps in confirming whether the current process is falling within pre-determined parameters.

Acceptance Sampling

Acceptance sampling is done on sample’s post production to check for quality parameters as decided by the organization covering both attributes as well as variables.

If the sample does not meet the required parameters of quality than that given lot is rejected, and further analysis is done to identify the source and rectify the defects.

Acceptance sampling is done on the basis of inspection, which includes physical verification of color, size, shape, etc.

The major objectives of inspection are:

• To detect and prevent defects in products and process.
• To identify defected parts or product and prevent it from further consumption or usage.
• To highlight the product or process defect to appropriate authorities for necessary and corrective actions.

Scope of inspection covers input materials, finished material, plant, machinery etc.

To sustain quality of product and services it is important to have in place robust quality control techniques.