SPC, or statistical process control, is one of the most interesting tools in the context of quality management. Nowadays, this method is widely used in the industrial sector. During this process, data is gathered for report preparation base on control cards. Meanwhile, by gathering and displaying measurements in real-time, we are able to decrease the reaction time for a process that is becoming unstable by using condition-based monitoring.
Above all, the implementation of automated SPC enables you to better monitor process behaviour and faster discover issues in internal systems. How does it look like in practice? The basic idea is a data gathering system. This data – which is intended to be used in the preparation of the report – is based on control charts. By gathering the data and displaying the measurements – which is done in real time – it is possible to reduce the response time for this process, which requires monitoring. It is not only a question of planning and defining quality, but also of manual data gathering and automatic data gathering from production measurements. What do you need to pay attention to in this process?
Manual gathering of data and possible challengesIt is worth highlighting that the traditional formula of data collection is a far cry from the challenges of daily life, which of course are dominated by ubiquitous automation. This is a path where one has to reckon, above all, with the possible delay of the information obtained. Manual data gathering leads to a lack of automatic notifications, such as the status of a part, to the quality department. However, manual data gathering cannot be reduced to this disadvantage alone. Others include:
- uncontrolled measurements, e., no confirmation that the measurement was carried out at specific intervals and for a specific number of items,
- unclear and inaccurate documentation,
- double reporting when transferring measurements to and from paper into quality systems,
- increased risk of human error,
- lack of fast reaction when a process becomes unstable.
Automatic data gathering – benefits of implementationWhen comparing automatic data gathering to manual data gathering, it is hard to overlook that there are clear advantages in certain cases. The main advantage lies within the many possibilities of automatic data gathering – this concerns both the sources and the way of collection and processing in general. The increase in possibilities in this area can be seen in the collection of data, even directly at the level of machine automation. In addition, automating data gathering for the SPC report also enables the implementation of solutions such as
- installing machine vision – cameras, scanners, x-ray devices – to obtain information for reports,
- obtaining data from devices – g., scales, check weighers or machines with a specific application,
- quality control with robots,
- manual measurements by tools with automated data sending (ex. Bluetooth caliper).
How does automatic data gathering work in the ANT system?The implementation of technology provided by ANT uses a quality control module to simplify, speed up, and control the results of quality measurements. The increase in efficiency also applies to the way data is collected automatically. The system proposed by ANT focuses strongly on the issue of integration and interaction of the individual components of the overall system. This applies, for example, to the combination of cameras with the quality module and MES. It also considers the installation of sensors and the integration of hand-held tools. The communication system is worthy of mention since it is extremely intuitive. Most importantly, however, the user is guided step by step through the entire operating procedure – this includes how to take measurements. Manuals, documentation, pictures and films form the basis for this. Intuitive operation also characterizes the control panel. It guides the user through the quality control process with the help of automatic pop-up windows. These pop-up after a certain number of hours or other parameters – e.g., the number of pieces produced, or the materials created at a certain time after a changeover or failure. After entering the measured value, the system can compare the result with the quality limits. Here, too, the output of the data display is completely optional and can be adapted to, for example, the permissions of a given employee. Operators can therefore display a control chart for their shift and the selected parameter. If a certain measured value is outside the tolerance limits, the system automatically sends the relevant notification. The comfort of use is also influenced by:
- variant to establish rules for triggering quality control,
- labelling of samples and handling of instructions,
- automatic generation of the SPC report in the form of control charts and histograms for various parameters.