**4. Green, lean and smart microfactory: chicken body as a model**

The oviduct of a chicken is a factory that produces eggs. An oviduct is the hen's reproductive system. It is a long spiraling tube. There are five major stages in the manufacturing of an egg. These stages and the cycle times of each stage are shown in **Figure 4** [20]. The journey of the chicken egg starts as an egg yolk. First, a follicle or the oocyte (still unfertilized) is made in the ovary, and as it moves through the oviduct by a small distance, it may be fertilized internally (life is created) by a

**Figure 4.** *Manufacturing stages of a chicken egg production in oviduct.*

sperm (stored inside the hen) and compacted into a spherical shape. Once the yolk attains a predetermined size and shape, its growth of stops. This process takes about 30 minutes. The yolk continues down the oviduct (whether it is fertilized or not) and is covered with a membrane (called the vitelline membrane), structural fibers, and layers of albumin (the egg white). This part of the oviduct is called the magnum. As the egg goes down through the oviduct, it is continually rotating within the spiraling tube. This movement twists the structural fibers (called the chalazae to hold the yolk in the center of the egg, against the forces of gravity), which form rope-like strands that anchor the yolk in the thick egg white. This process of two chalazae anchoring each yolk, on opposite ends of the egg takes about another 2 hours. Then, two egg membranes made of keratin, are wrapped around the albumen to keep it in an ovoid shape. Then in the lower part of the oviduct, the synthesis of eggshell takes place, which takes about 20 hours. The shell is made of calcite, a crystalline form of calcium carbonate. Eggshell is not a solid wall, but porous with about 7000 to 17,000 holes. These pores allow the exchange of gases during the development stage. The cloaca secretes the egg's outer cuticle and shell pigment. Then, the egg is ejected out of the hen's body. Eggs are usually laid blunt end first. An air space filled with Oxygen forms when the contents of the egg cool and contract after the egg is laid. The embryo consumes this Oxygen as it grows into a chick during the hatching process.

Material transforms while moving through the tubular factory with minimum energy requirements in the conversion process. The oviduct is like a moving workshop, a silent and lights-out factory, where an egg is manufactured, at the rate of one egg every 24 hours. An egg, when hatched, transforms into a new factory (chicken) that can produce more eggs, with the egg's DNA blueprint. All parts of an egg are fully upcyclable. No part causes any damage to the environment (except the largescale waste from the industrial poultries). A discarded egg putrefies and decomposes enriching the soil. Other birds and animals eat leftover eggshells to supplement their calcium intake. The chicken body and the "oviduct assembly line" are made of

*Principles for Designing Green, Lean, and Smart Microfactories: Chicken as a Model DOI: http://dx.doi.org/10.5772/intechopen.109645*

### **Figure 5.**

*Value stream map (VSM) of a chicken egg production process.*

biomaterials that are easily decomposed and upcycled. Considering that both the product (egg) and the manufacturing system (chicken body) are zero-waste systems, they can serve as models of a circular economy.

A Value Stream Map (VSM) of this manufacturing process in the oviduct is presented in **Figure 5** [21]. The inventory of protein, fat, calcium, and amino acids is approximately sufficient for just one day. The inventory in the chicken's body lasts for about a day, which is 24 hours. For the next day, for the next egg, fresh feed must be taken in by the chicken. There is no storage space for, say, many days of inventory. Some chickens might be fattened up, but there is a limit on how much a chicken can eat and store, which cannot be more than the inventory for a couple of days. From the inventory "turns" point of view, if a chicken is laying 400 eggs during the egg-laying period in a year, the number of inventory turns is 400. Because each egg is produced with a one-day worth of inventory, 400 is a very high number, far beyond what has been achieved by any human-built factory. The value addition percentage is also close to 100% which has not been matched even by the best lean manufacturers in the world. The physical, green, lean, smart, and operational attributes of this factory are summarized in **Tables 4**–**8**.

These characteristics listed in **Tables 4**–**8** clearly make it evident that the chicken body viewed as a microfactory is a green, lean, and smart manufacturing system. The chicken body is a lights-out factory with no workers, no supervisors, no machines, no tools, and no technology experts. The chicken body is made of environmentally benign biomaterials, and hence, it is green. All materials of a chicken's body are completely upcyclable. Millions of sensors in a chicken's body are connected to a central nervous system. When we apply the concepts of lean, Industry 4.0, or sustainability, we get answers that confirm that the chicken microfactory is extremely lean, highly automated, and 100% green. The lights-out score of this microfactory will be the highest compared to any human-built factory embracing the principles of green, lean, and smart. From the moment the first single-celled organism was born,


### **Table 4.**

*Microfactory physical attributes.*


### **Table 5.**

*Microfactory attributes (green).*


*Principles for Designing Green, Lean, and Smart Microfactories: Chicken as a Model DOI: http://dx.doi.org/10.5772/intechopen.109645*


### **Table 6.**

*Microfactory attributes (lean).*


### **Table 7.**

*Microfactory attributes (smart).*


### **Table 8.**

*Chicken body microfactory attributes.*

about 3.5 billion years ago, nature has been using only green and lean principles in its creation. The key to nature's "lean" processes are nanotechnology and self-assembly which do not require enablers like machines, tools, workers, and supervisors. Nature's factories are significantly more efficient than the best factories in our industrial world like Toyota, GE, Dell, or Apple. Nature's factories score much higher scores on "green, lean, and smart" metrics than the best modern factories. Similarly, nature's products are designed intelligently with nature-friendly materials, manufactured efficiently with no pollution, and upcycled completely after their useful life. In this sense, nature factories and products are perfectly created for the circular economy.

## **5. Green, lean, and smart factories**

Lean manufacturing and later lean thinking have revolutionized the manufacturing and service sectors. Intellectuals and business leaders such as Frederick Taylor, Henry Ford, Sakichi Toyoda, Kiichiro Toyoda, Taiichi Ohno, Shigeo Shingo, Masaki Imai, Edward Deming, Joseph Juran, Kaoru Ishikawa, and James Womack have contributed to the knowledge of lean. The publications of the International Motor Vehicle Program (IMVP) [22] at MIT, Cambridge, MA, and the Lean Enterprise Institute (LEI) [23] have further promoted the implementation of lean across the globe. As lean thinking continued to spread to every country in the world, leaders have been adapting the tools and principles beyond manufacturing, to supply chain, logistics and distribution, services, retail, healthcare, construction, maintenance, and even government. The first report "Industry 4.0 and the Internet of Things" was published by Hannover Messe in 2013 [24]. With the advent of Factory 4.0 and Industry 4.0 technologies, lean is further fine-tuned to gain more productivity, efficiency, and quality. Hundreds of companies have been implementing Industry 4.0 technologies, and many smart manufacturing hubs are established all over the world. Recent advances in biomaterials and new technologies such as 3D printing and 4D printing [25] have been shifting design and manufacturing closer to a circular economy and bio-inspired manufacturing methods [26, 27].

Millions of products (grains, fruits, vegetables, fibers, eggs, etc.) in nature are manufactured in focused factories. For example, a tomato plant that produces vegetables, or an almond tree that produces nuts, or a bird that produces eggs are focused factories. The basic concepts and characteristics underlying the focused factories are simplicity and repetition that give consistent delivery performance [28]. Chicken body is like a focused factory which produces a single product (egg) at low cost, high quality, with consistent lead times, and with low investment. In this chapter, an attempt is made to look at the chicken oviduct as a model for sustainable design and manufacturing. The preliminary analysis presented in this chapter shows that "chicken microfactory" can serve as a benchmark "green, lean, and smart" metrics for human-built products and manufacturing systems.

## **6. Principles of microfactory design**

Microfactory is a small-to-medium scale, highly automated, and technologically advanced manufacturing setup, which has a wide range of process capabilities [29]. A microfactory either refers to a local capital-lean facility used for the assembly of a complex product or a small manufacturing system (normally automated) for producing small quantities of products. The Mechanical Engineer Laboratory (MEL) of Japan proposed the term "microfactory" in 1990. Currently, microfactory describes the small-to-medium scale, highly automated manufacturers like Arrival Ltd., an
