The John Guest model is increasingly unique in an era of outsourcing and diversification. Strict control over the entire design and production process ensures the production of only the highest quality products. This vertically integrated supply chain means that the entire journey of a product from the initial concept, tool design and tool making, to the production, assembly, and testing of the product is fully undertaken by John Guest. While this philosophy provides maximum control and accountability over the quality of the product that leaves the production line, it also gives John Guest flexibility to respond quickly to customer ideas and or market trends.