Quality control and surveying the capability indices of the saffron production process

As the world's most expensive agricultural and medicinal product, saffron holds a special place among Iran's industrial and export goods. Customers constantly seek the best products in terms of price, quality, and timely delivery. Thus, it is crucial and necessary to ensure quality control in the saffron production process in order to satisfy customers and enhance profitability. To thrive in the competitive market, greater attention should be given to the critical quality characteristics of saffron, namely crocin, picrocrocin, and safranal. Moreover, statistical process control, a method for monitoring processes to identify the underlying causes of specific changes and deviations, is essential. Control charts and process capability indicators serve as necessary tools in statistical process control. Therefore, this paper primarily focuses on the use of the exponentially weighted moving average control chart, which is effective for handling minor deviations, to monitor and control the saffron production process in a data set during the initial phase. The data sets pertain to the qualitative characteristics of saffron in the cities of Torbat Heydarieh, Zaveh, Roshtkhar, Bardeskan, and Kashmar. Following the examination of the quality aspects of the saffron production process and its sustainability, emphasis is placed on the control chart as the most crucial statistical process control tool. Efficiency indicators of the saffron production process are then calculated and analyzed using standards 259-1 and 259-2. Through this analysis, efforts can be made to reduce process variability and consequently compare and enhance the quality level of saffron produced in the investigated areas. The results showed that in premium cut string saffron, Torbat Heydarieh city has the best picrocrocin, Kashmar city saffron has the best safranal, and Rashtkhwar city saffron has the best crocin. Also, the best picrocrocin and saffron type 1 string saffron belong to the town of Torbat Heydarieh and the best safranal belongs to the town of Bardeskan. Utilizing these indicators in the saffron production process serves as a measure to evaluate the processes' ability to meet customer demands and comply with relevant industry standards.