Allion Labs

What is IPQC?

Input Process Quality Control (IPQC) refers to quality control in the input process of raw materials, production, and packaging.

IPQC emphasizes two key points:

  1. Verification of the first product of a batch from a new product line or a line that has switched products and establishment of product standard in the production department, and
  2. The inspection standards for the products in production shall be controlled based on the first sample, meaning that all of the products in the official production shall meet the requirements for the first sample, and that the raw materials shall be verified as correct before the production begins.

Why is IPQC important? What are the goals of IPQC? What is the role of IPQC?

Quality is decided in manufacture and not by inspection. However, inspection can be used to improve product quality. The goals are to prevent substandard products from appearing and to prevent them from entering the next step in the manufacturing process. The goals of IPQC are to discover existing potential quality issues through on-site inspection, and to prevent the aggravation of potential quality issues into quality incidents. However, IPQC is not only a control measure but also a way to turn inspection results into messages for quality improvement and in turn, actions for quality improvement.

Work content (duties), standard inspection and established procedures of IPQC

Simply put, in order to prevent the massive appearance of substandard products, the IPQC process inspection inspects not only products but also the main factors affecting product quality, including Man, Machine, Material, Method and Environment, or what is called 4M1E.

In fact, in the manufacturing of mature products, any quality issue can be attributed to variations in one or more factors of the 4M1E. Therefore, the process inspection serves two purposes:

  1. Determination on the product based on the inspection results, that is to say, whether the product quality satisfies the requirements of specifications and standards, and
  2. Determination on the process based on the inspection results, that is to say, whether the factors of the process are in a normal and stable state.

Then, the decision can be made on whether to continue production.

The IPQC process inspection usually consists of three formats, namely first inspection, patrol inspection and last off inspection:

1. First inspection

First inspection is the inspection of the first piece. It is an effective measure to spot issues early on and to prevent entire batches of products from going to waste. Through first inspection, systematic causes such as severe wearing or wrong installation or positioning of tools or fixtures, deteriorated precision of measuring instruments, wrong reading of diagrams, wrong input of materials or formulas can be discovered. Corrective or improvement measures can then be adopted to prevent the occurrence of entire batches of substandard products.

First inspection shall be implemented in the following situations:

  1. When a product is first produced.
  2. When equipment is recalibrated or when there is a major change in techniques.
  3. When there is a change in shifts or operators.
  4. When there is a change in the type or material of semi-finished products.

First inspection is usually implemented in three steps, namely self-inspection by operators, second inspection by supervisors or QC staff, and final specific inspection by inspectors. For massively produced products, the “first piece” is not limited to a single piece but can be a certain number of samples.

2. Patrol inspection

Patrol inspection is implemented by inspectors at the work or production sites in a specific order at fixed time intervals and routes, sampling recently produced products to see whether they meet the specifications in diagrams, or technique or inspection manuals. In mass production, patrol inspection is usually combined with the use of process control chart to avoid anomalies in the production process to prevent the occurrence of entire batches of substandard products.

3. Last off inspection

Quality of the production process is ensured by molds or installations. When the production for a batch of products is complete, the last product is sampled for full inspection. If defects in the molds or installations are discovered, the molds or installations can be repaired before the next production to avoid affecting production due to defects discovered after the next production begins.

The standard inspection process of IPQC is as follows:

This concludes the overview of IPQC, and in the next article, we will introduce the service features of IPQC of Allion and answer some common questions related to our products to help you understand IPQC applications.

Take the Next Step

If you want to improve your product in the IPQC process, the Allion team is at your service! Learn more about our quality control services or email us directly at