**5. Discussion**

Subscription could be topic-based, content-based or a hybrid of these two. In a topic-based subscription a subscriber subscribes for an events published with some topic. In a content based subscription, subscriber receives an event if a content of the event matches to the con‐ straints defined by subscriber. Traceability architecture support hybrid of these two. IAD event providers publish events of a topic and subscribers can define content based subscrip‐ tions to one or more topics. For example - as illustrated in Figure 14Example IAD event data

**•** A LogHarvested event which contains the exact volume, quality and price information

**•** A HarvesterState event which contains information about harvester state (battery, fuel,

LogHarvested

HarvesterState

There are three different subscribers for the event LogHarvested. Saw mill production plan‐ ner wants to preplan the production beforehand by knowing the quality and amount of logs that are about to arrive to the saw mill. Saw mill purchaser makes payment based on the log volumes harvested and Traceability application gathers the information for research. For the event HarvesterState there are two subscribers. Traceability application gathers data for re‐

By combining information throughout the supply chain the Traceability Services enables new methods of analyzing the wood material. The properties of wood object can be com‐

For example length in harvesting vs. length in log sorting. Another possibility is to analyze how some property affects some other property. For example, how an area of origin affects

pared between different steps, see Figure 15 Supply chain steps with properties.

search and Harvester company can monitor its harvester status.

Saw mill Production planning application

Saw mill wood purchasing application

Traceability applicaltion

Harvester company ERP

A harvester publishes two events with different topic:

320 Radio Frequency Identification from System to Applications

flow.

about log harvested

Harvester#1

**Figure 14.** Example IAD event data flow.

the board quality.

position, etc…)

The forest industry represents some unique challenges to the traceability solutions – the da‐ ta is utilised by different actors in the value chain so that typically the information is pro‐ duced by one party and the information needs to be utilised by another party that may be outside the supply chain. The basis for the traceability and information utilisation is reliable and affordable identification of the wood. By identifying the wood material and items in the supply chain the associated information can be utilised by different parties. This enables new level of control of the wood conversion chain, tailored and specialised products, and new business models.

The main challenge in enabling the possibilities of the traceability in the forest industry has been the lack of a reliable and inexpensive means to identify automatically the logs and boards in various processing steps along the wood supply chain. The optical marking tech‐ niques such as printed markings offer the potential for very low costs but these methods struggle to reach better than 90-95 % success rate in the automatic identification of the wood items in industrial production conditions. The required identification success rate has to sig‐ nificantly exceed 99 % so that the information retrieval becomes a viable option for reacquir‐ ing the needed information, e.g. log dimensions. With 90-95 % identification success rate the risk for not being able to retrieve the needed data is some 10 times larger than what is gener‐ ally considered acceptable – the benefits of the traceability are quickly lost if the information cannot be retrieved for a significant percentage of the wood items.

RFID technology offers the potential for near 100 % success rate in the identification of logs. The main challenge is the cost of the transponders – the acceptable cost for a transponder depends on the value of the wood material in question and on the expected savings and benefits to be obtained through the use of RFID. Currently the acceptable price for RFID var‐ ies case by case and there are different opinions on the price level. The price of the tags de‐ pends greatly on volumes – large scale mass production lowers the unit price considerably. For a hard tag the price may go as low as a few cents if there is market for sufficiently large volumes – large numbers of tags are needed to push the price down but before the prices are affordable there is not much demand for the tags.

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

, Ville Puntanen2

1 Sensing and Wireless Devices, VTT Technical Research Centre of Finland, Espoo, Finland

[1] Product images, Ponsse, http://www.ponsse.com/media-archive/images/products

[2] Usenius, A., Heikkilä A., Usenius T., Future Processing of Wood Raw Material, Pro‐ ceedings of the 20th International Wood Machining Seminar, June 7 -10, 2011, Skel‐

[3] Dykstra, D. P., Kuru, G., Taylor, R., Nussbaum, R., Magrath, W. B., Story, J., Technol‐ ogies for wood tracking, In: Environmental and Social Development East Asia and

[4] GS1. Bar code types: http://www.gs1.org/barcodes/technical/bar\_code\_types (ac‐

[5] Juurma, M., Tamre, M., Infrared radiation excited pigment marking technology. In: Proc of 12th International Symp Topical Problems in the Field of Electrical and Pow‐

[7] Möller, B. Design, development and implementation of a mechatronic log traceability system. Doctoral thesis, Royal Institute of Technology, Stockholm, Sweden, 2011.

and Kaj Nummila1\*

Challenges and Possibilities of RFID in the Forest Industry

http://dx.doi.org/10.5772/54205

323

low prices for tags if compared to printed markings.

\*Address all correspondence to: kaj.nummila@vtt.fi

, Kaarle Jaakkola1

Pacific Region Discussion Paper, World Bank, 2002.

er Engineering, Tallinn, Estonia, 2012, pp. 149-150.

[6] Indisputable Key, Final report, Deliverable D1.24, 2010.

, Antti Sirkka2

(accessed 3 September 2012).

lefteå Sweden, pp. 1-9.

cessed 3 September 2012).

2 Tieto Oyj, Tampere, Finland

**Author details**

Janne Häkli1

**References**

The main challenge in achieving near 100 % identification success rate in RFID based log marking is the application of the tag – the insertion of the transponder into the wood. This has to be done automatically so that the log production efficiency is not significantly re‐ duced by the log marking. Several prototypes of automatic applicators for forestry harvest‐ ers have been developed in different research projects but so far no device suitable for long term production use has been successfully built. This is the main technical challenge to be solved before the RFID based log marking can be adopted in large scale in the forest indus‐ try. Current solution allows manual tag application for small scale (up to a few thousand logs) log marking, e.g. for marking log batches and piles, or test logs for research and testing purposes, or marking tree trunks or logs when trees are felled manually using chain saws.
