The following six principles should be considered when applying digital tools to lean manufacturing:
In order to get a higher level of responsiveness and operational transparency, paper documents should be removed. Instead, manufacturing apps on wearable devices allow to create fully digital workflows for efficient data acquisition and task coordination.
While many side-by-side IT solutions existing in current factories, the number of these systems should be kept to a minimum. In addition to the ERP system for production planning and control, a central MES or task management system for the collection of data from operational processes is needed. This includes the collection of machine data, quality data, process data, batch information etc. To enable an aggregated view on all data, all IT solutions should be able to exchange data through standard interfaces such as REST APIs, OPC UA or MQTT.
Detailed planning of the core processes is an important factor for operational efficiency. For the smart factory, planning functionalities are required that enable fine planning in real time. With this, knowledge of the actual situation should be taken into account. Access to relevant data from the aligned IT solutions is a prerequisite. For example, the production planner should be able to see both the current order status and the status of the respective machines. Hence, he can react to changing situations as quickly as possible and can ensure that all orders get produced without interruptions. To enable detailed planning in real time, digital tools with instant feedback mechanisms such as smartwatches worn by the workers are important.
In most factories the production orders are centrally planned for the entire factory. This results in rather static processes. A higher autonomy of the production areas is recommended. Compared to centralized planning offices on the “top floor”, a decentralized setup on the “shop floor” allows fast and on the spot decisions. Of course the fine planners in such a setup must have access to the planning tools and must be trained for detailed planning in real time.
In many factories, planning processes are still paper-based and rather static, e.g. planning boards with paper sheets. With this, the individual production areas are not well connected and follow the rhythm of the flow of paper sheets. In a smart factory not only the order statuses of the individual production areas must be synchronized, but also the supporting processes should be aligned. This includes information exchange related to detailed planning, toolmaking, maintenance, quality assurance, etc. Digital tools allow information updates on request, e.g. smartwatch apps provide real time information about machine changeover times. Thus, it can be ensured that all process participants receive the same information, e.g. regarding the current planning status or regarding the status of replenishment orders.
All data from the decentralized production areas must be made available on a centralized server. With a centralized server operational data can be accessed from all functions at any time. This includes order status, machine status, personnel information, quality data, process data from sensors, etc. This centralized server, e.g. deployed in a private cloud, is an important part for the smart factory infrastructure.