### Product Recycling Desirability Model  
Although numerous approaches to increase recycling rates have been investigated in the literature, the Product Recycling Desirability Model (PRDM) was coined as a competent model for prioritizing product selection for recycling due to its successful application in several international cases, including those of the United States, the United Kingdom, the European Union, China, and India [29]. The model's critical parameters were: (i) the ease with which the product's components could be disassembled for recycling, (ii) the readiness of the recycling technology in place to carry out the recycling operation; and \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Rank** & **UK** & **EU** & **India** & **Australia** & **Japan** \\ \hline
1 & Gold & Dysprosium & Strontium & Gallium & Neodymium \\
2 & Rhodium & Magnesium & Phosphate & Indium & Dysprosium \\
3 & Mercury & Samarium & Potash & Tungsten & Indium \\
4 & Platinum & Gadolinium & Vanadium & Cobalt & Niobium \\
5 & Strontium & Rhodium & Boron & Niobium & Tin \\
6 & Silver & Tungsten & Barium & Manganese & Silver \\
7 & Antimony & Neodymium & Lithium & Molybdenum & Zinc \\
8 & Tin & Cerium & Chromium & Antimony & Tantalum \\
9 & Magnesium & Holmium & Molybdenum & Lithium & Manganese \\
10 & Tungsten & Lutetium & Silicon & Vanadium & Cobalt \\
11 & Baryte & Terbium & Niobium & Nickel & Gold \\
12 & Talc & Thulium & Cobalt & Tantalum & Platinum \\
13 & Bismuth & Ytretibium & Limestone & Terbium & Iron \\
14 & Palladium & Antimony & Selenium & Chromium & Rhodium \\
15 & Nickel & Phosphorus & Antimony & Selenium & Palladium \\
16 & Boron & Niobium & Gypsum & Titanium & Lead \\
17 & Andalusite & Erbium & Nickel & Strontium & Copper \\
18 & Molybdenum & Cobalt & Bentonite & Graphite & Chromium \\
19 & Zinc & Palladium & Germanium & Tin & Molybdenum \\
20 & Holmium & Bismuth & Graphite & Germanium & Tungsten \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Top 20 critical materials for the UK, the EU, India, Australia and Japan. (iii) the criticality of the materials contained in end-of-life products, which make them prime candidates for recycling. Equation (1) shows the product desirability calculation by [29]. \(D_{Desirability}\) is the desirability recycling index for the selected product and is calculated considering the index of ease to disassemble the end-of-life product, the product's material security, and the recycling technology readiness index. \[D_{Desirability}=\left(D_{Simplicity}+D_{MSI}+D_{TRL}\right) \tag{1}\]  
Equation (2) illustrates the ease of material separation, \(D_{Simplicity}\), considering mass fraction and distributed materials for parts. Where \(H\) is the inverted complexity measure which is known as the simplicity index. \[D_{Simplicity}=1-\left(\frac{H}{H_{top}}\right) \tag{2}\]  
It assesses the ease with which materials in a product can be disassembled quantitatively, as proposed by [30], using a complexity theory. A parameter \(H\)(bits) based on binary separation steps is used to quantify this. This is the collection of individual separations that are gradually required to separate a product's materials. A product with fewer separation steps would have low material mixing, whereas a product with more separation steps would have higher material mixing. Material security is the availability and access to the material resources upon which economies rely, as well as the capacity to withstand volatility, increasing scarcity, and rising price [29,31]. The presumption is that there will be no adverse effect on the country's economy as a result of a shortage or restricted access to the specified substance. Material security is a negative indicator, implying a lack of scarcity in order to achieve the lowest acceptable limit, rather than a positive requirement for abundance. The material security index for recycling, \(D_{MSI}\) is shown in Equation (3).