Industrial revolutions have gone through four phases: steam, electricity, electronics, and Industry 4.0. Through all these four industrial revolutions, efficiency, productivity, quality, and automation have been greatly improved. However, the manufacturing processes created by humans have had disastrous consequences on the environment leading to a gigantic “climate change” problem. To mitigate climate change, engineers, and manufacturers all over the world have stepped up the research into cradle-to-cradle designs and sustainable manufacturing practices inspired by the designs and value cycles in nature. Bio-inspired designs have been gaining momentum to create products and manufacturing methods that are eco-friendly. All manufacturing (of a fruit, an organism such as a human baby) in nature happens in microfactories such as a womb, a leaf, a flower, or a chicken oviduct whose products are eggs. The product (egg) and the manufacturing process (chicken oviduct) are both green (eco-effective), lean (built with minimal resources), and smart (sensors and Internet of Things). Using a chicken as a model, this book chapter presents a set of metrics for green, lean, and smart attributes, which engineers can use to design products and microfactories.