Impact of warranty and green level of the product with nonlinear demand via optimal control theory and Artificial Hummingbird Algorithm.

Due to the current environmental situation and human health, a green manufacturing system is very essential in the manufacturing world. Several researchers have developed various types of green manufacturing models by considering green products, green investments, carbon emission taxes, etc. Motivated by this topic, a green production model is formulated by considering selling price, time, warranty period and green level dependent demand with a carbon emission tax policy.

Inventory model for green products with payment strategy, selling price and green level dependent demand using teaching learning based optimization algorithm.

There has been a lot of research on pricing and lot-sizing practices for different payment methods; however, the majority has focused on the buyer's perspective. While accepting buyers' credit conditions positively impacts sales, requesting advance payments from purchasers tends to have a negative effect. Additionally, requiring a down payment has been found to generate interest revenue for the supplier without introducing default risk.