**6. Conclusion**

There are three main types of situations where traceability can be utilized to gain production improvements in forest industry: trouble-shooting, production optimisation and data min‐ ing. Trouble-shooting occurs when some end-product or batch deviates from the target quality. With traceability it is possible to trace the defect of quality to its root cause. For ex‐ ample it could be connected to the specific kiln in the saw mill or to a wood batch and its processing history.

Optimisation can be achieved using the traceability information. For example if the spiral grain angle of a log that has been used to produce a board is known, the twist of the board can be estimated. Using this information the board can be placed as a bottom of the drying patch. This can reduce the final twist of these boards by 50%. Traceability information can be used to mine the different correlations between wood properties. For example a window frame producer needs boards with long average distance between knots and wood with this property can be assigned for production of boards for this end product.

The basis of the traceability is reliable identification of wood items to associate and retrieve information on them. To identify the logs in the Nordic round wood supply chain a novel UHF transponder was developed together with robust RFID reader solutions. The novel wedge-shaped transponder is made from pulping compatible materials and it is inserted in‐ to the log end. In trials in saw mills the transponder readability was close to 100 % for intact functional tags. An ICT system solution was also developed for the data storage and transfer to utilise the collected information by different actors in the value chain.

The future development of the RFID based traceability should focus on further improving the reliability of the tracing close to 100 % for all logs. The main technical development needed is an automatic applicator suitable for production use in forestry harvesters to ach‐ ieve high success rate in fast application of tags into logs. For marking high volume lower value items such as boards an inexpensive but sufficiently reliable identification method is needed – currently used printed markings are inexpensive but not highly readable in pro‐ duction conditions. UHF RFID technology has high readability but there are some technical challenges such as the application to the boards to solve – it is also difficult to achieve very low prices for tags if compared to printed markings.
