Track & trace of components to avoid expensive rework and recalls

Tracking & Tracing – Core function of MES-Solution Legato Sapient

In industrial production, the finely orchestrated interaction of all components, raw materials, production status, knowledge of storage locations and other components is crucial. Ensuring this on a daily basis is a major challenge for companies in a variety of industries. When audits, certification requirements, or recalls come into play, it is elementary to know what the status of production is at all times.

A recall is the worst-case scenario for any company. It leads to enormous costs and makes for negative headlines. Recalls are by no means uncommon. According to statistics, there are approximately 300 product recalls in Germany alone and over 2,000 Rapex notifications from the European member states each year. The resulting costs can quickly run into tens of millions of dollars, which means that reducing these scenarios by just 1% can save an enormous amount of money.

The best way to avoid them is to identify quality problems in production at an early stage and take immediate action. If a recall is necessary in spite of everything, it must be fast and targeted. However, the ever-increasing demands and increasingly complex processes are difficult for humans to handle by themselves. Automated solutions are needed that can support both the guarantee of quality standards and the continuous improvement of production processes.

Traceability software can be used to guarantee complete traceability within production processes. The main objective here is transparency: from the raw part, through the production process of the individual parts, to the end product. This is made possible by linking production orders with unique serial numbers of the individual parts. The technologies used for this can be, for example, barcodes, labels, FINs, lot, serial and batch numbers, Data Matrix codes or an RFID chip. If the solution is linked to the MES in a process-oriented manner, other data from the shop floor can also be added and linked. Consequently, almost any data record can be assigned to a product through track and trace.

Tracking & tracing is a core function of the Legato Sapient MES solution. It enables seamless tracking and tracing of all products, including all product-relevant data – throughout the entire manufacturing process. In this way, a complete image of each production unit is created – a digital twin. This includes all product data (such as order, type, characteristics, quality status), product-related process data (such as torques, temperatures) and product-related plant data (such as status, malfunctions).

Digital Twin

1. Enabling a 360° all-round view for track & trace with the MES as a key player

The recording of raw materials, intermediate or end products via corresponding reading points in the process is a practicable method, but there is more to a fully comprehensive Track & Trace than that. 60% of production companies use tracking & tracing only half-heartedly. Full potential benefit is only possible in combination with MDE and BDE. This includes automated data collection from the production process (online, real-time) to guarantee high data quality and real monitoring of the actual situation. Furthermore, tracking & tracing via an MES as a global control station has the advantage of being able to view and analyze the complete recording of all product-relevant data over the entire production process (from raw material to end product) at any time – unlike, for example, data stored on local RFID data storage devices. An MES can act as a central data hub for this purpose, providing not only transparency within the entire production area (horizontal data integration), but also real-time information from the shop floor for the business level (vertical data integration). With all the collected and stored data, a variety of aggregated values and key figures can be generated (e.g., processing and transport times, degree of quality), which serve as the basis for the continuous improvement process (CIP) and thus enable an increase in efficiency with regard to costs, time and quality.

Image: Unification of many and complex data into one whole. The production unit (PU) with all associated data and information.

2. Process interlocking – not only Track & Trace, but also Control

When it comes to transparency, the complete collection of data is essential. In addition, however, today’s modern tracking & tracing in terms of quality control should not only be used for prevention and monitoring. Rather, it should also include functions for quality control, in order to be able to initiate appropriate processes when components or batches of insufficient quality are identified. Control can be automatic, i.e. event-controlled via defined process limit values and monitoring of the actual values from the controls, or it can be carried out by manual identification of a production specialist. If a production unit (PU) in the production flow is assigned a blocking status, this process value is documented in its life file. Corresponding entries in the blocking list stop further processing of the PU concerned, enable early ejection and thus prevent unnecessary and cost-intensive further processing in the subsequent production process.

3 Carrier management – integration of means of transport

For some production processes, it is not possible to transport the production unit itself. For this purpose, special means of transport are used as “work piece carriers”. Carriers or SKIDS have their own ID (carrier ID), which is used for identification at the reading points. The production unit is then identified indirectly via the carrier ID, with which the PU ID was “married” during merging. This is nowadays a standard method to establish the link between the identified carrier and production unit. Without a central system like the MES, the identification at a reading point is done exclusively for the upcoming production process to perform the operation, i.e. without tracking the carriers. With an MES, the recorded information of the means of transport can also be tracked. Thus, tracking in real time is possible. Additional information (e.g. route, number) supports the coordination and provision of the means of transport (at the right place at the right time), which in turn improves organizational availability. Insight into deployment duration and frequency also enables improved maintenance in terms of predictive maintenance.

Carrier Management

Image: Identification and storage of work piece carrier IDs as the basis for far-reaching carrier management.


Example: Track & Trace – Locating production units → Goal: Information on identified production units for the production area “final assembly” in plant 2, checking the quality status, changing the Q status of a production unit.

  • Initial situation: Due to problems detected with a tool (screwdriver) in the final assembly of line 1, the production units affected by this must be identified in the sense of “tracing”.
  • Goal: Identify the affected production unit(s), check and, if necessary, change the quality status in order to block corresponding products for further operations (eject, separate quality check, if necessary rework, reject or reinsert).

Step 1: Selection of the T&T Dashboard “Overview

The dashboard provides all information on the T&T reading points (identification points) and the production units identified via them. The navigation tree (logical production structure) is displayed in the left pane. There are no read points for the currently selected node “Plant 3” and therefore no information is displayed on the “Read points” and “Production units” boardlets.

Step 2: Selection of the relevant production area

With selection of the relevant production area (final assembly, line 1) in the navigation tree, the contents of all boardlets are updated. On the “Reading points” boardlet, all reading points of line 1 and the PUs (production units) last identified via them including the identification time, are displayed.
On the “Production units” boardlet, all production units are listed that were registered at the reading points shown above, with details of each PU-ID. As an additional filter criterion, the time range can be set (e.g. temporal occurrence of the assembly problems and thus possibly affected production units).

Step 3: Selection of a reading point

To narrow down the search radius of affected PUs, the list of production units identified here can be filtered by selecting a reading point. The production units now identified (in the example, only one PU with ID “PU0000002”) are displayed.

Step 4: Selection of a PU

For the PU with ID “PU00002”, all important data at the current time are displayed in this view (e.g. last identification, status). Double-click on this PU to open a detailed view.

Step 5: Detailed view of the PU

The detailed view shows the complete tracking history of the PU, which is based on the identification at the individual reading points, in combination with automatically recorded process/machine data and operator inputs. Thus, in terms of tracing, the entire logged process can be viewed and analyzed. For better analysis, the view of the “Production Unit Details” boardlet can be maximized and the side navigation tree can be hidden.

Step 6: PU history analysis

With appropriate rights, tracking data can be added or changed. This can include changing a quality status in order to block the part for further follow-up processes when it is changed to n.O.K. (not O.K.) and to trigger follow-up actions (e.g. divert, rework). Selecting the data record by double-clicking activates a processing mode.

Step 7: Analyzing the PU history

In edit mode, it is possible, among other things, to change the PU status (e.g. released, locked) or the Q status (e.g. n.O.K. for quality inspection). A preconfigured selection list with the possible states enables easy selection of the parameters. When the changes are accepted, this PU history is updated or extended.