With the new global economy, manufacturing companies are focusing their efforts on the product development process which is fast emerging as a new competitive weapon. Several product development solutions allow engineers, suppliers, business partners and even customers to collaborate throughout the entire product lifecycle via the Internet. To gain an additional edge over competitors, it is vital that companies utilize web logs to discover hidden knowledge about trends and patterns in such a cyberworld. However, existing web log mining techniques are not designed for web logs generated by product data management processes. In this paper, we propose a method termed Product Development Miner (PDMiner) to mine such web logs efficiently and effectively using a trie structure and sequential mining techniques. Experiments involving real web logs show that PDMiner is both fast and practical.