In this research we develop mathematical models of Joint Economic Lot-sizing Problem (JELP) in a situation when a supplier offers time-based temporary price discounts to a buyer during a sale period. To respond this, the buyer places a special order with higher quantity. In literature, it has been assumed that the buyer tends to place the special order at the end of the sale period. We relax th...

knowledge of seasonal fluctuations is of great importance for sale management. the aim of this research is to assess the impact of sale season on the log and lumber prices. hence, after evaluation of sale documents in azarood forestry plan, the data of 410 timber sale lots at roadside of four seasons from 1992 to 2008 were extracted and incorporated into a dataset. calculating the average selli...

banking without usury is a very important object that has been considered by experts and investigated all time. in this writing, we have explored banking debt with known profit and concluded its rightness, based on soling debt right. in this way after lending money the bank sales it to debtor with agreed price. the way is similar about person's lending to bank and thus there is no usury. i...