Optimization of the Production Planning and Trade of Lily Flowers at Jan de Wit Company

Abstract

Jan de Wit Company implemented a decision-support system based on linear programming as a production-planning and trade tool for the management of its lily flower business. The LP maximizes the farm's total contribution margin, subject to such constraints as marketdefined sales limits, market requirements, characteristics of the production cycle duration, technical requirements, bulb inventory, and greenhouse limitations. The main decision variable to be calculated is the number of flower beds in a specific greenhouse, from a specific bulb batch, of a specific variety, for a specific purpose, taking into consideration planting and expected harvesting weeks. Between 1999 and 2000, company revenue grew 26 percent, sales increased 14.8 percent for pots of lilies and 29.3 percent for bunches of lilies, costs fell from 87.9 to 84.7 percent of sales, income from operations increased 60 percent, return on owner's equity went from 15.1 to 22.5 percent, and best quality cut lilies jumped from 11 to 61 percent of the quantities sold. The system also suggested changes in the product mix.

Food-Energy Interactive Tradeoff Analysis of Sustainable Urban Plant Factory Production Systems

“…The KKT conditions are necessary and sufficient optimality conditions for the profit maximizing problem [10,13,25]. The KKT conditions of all vegetable production firms in the market are derived and collected in Equations (17)- (22). Since Equations (13) and (14) are equality constraints, the corresponding dual variables (α fi and β fj ) are unrestricted in Equations (17) and (18).…”

“…Since Equations (13) and (14) are equality constraints, the corresponding dual variables (α fi and β fj ) are unrestricted in Equations (17) and (18). Otherwise, the dual variables are non-negative and the associated KKT conditions are derived in Equations (19)- (22). Collecting the KKT conditions yields an LCP model in Equations (17)- (22).…”

“…Otherwise, the dual variables are non-negative and the associated KKT conditions are derived in Equations (19)- (22). Collecting the KKT conditions yields an LCP model in Equations (17)- (22). Then, the LCP model is formulated on GAMS and solved using the PATH solver.…”

Optimizing the supply chain strategy of a multi-unit Finnish nursery company

“…Optimization-based decision-making systems for greenhouse-production have been developed previously, for instance, in the lily flower business (Caixeta-Filho et al 2002) and in potplant production (Saedt et al 1991). The main objective of Caixeta-Filho et al (2002) was to maximize the total contribution margin of the company studied due to optimizing the production variety of different plants by applying general linear programming.…”

“…The main objective of Caixeta-Filho et al (2002) was to maximize the total contribution margin of the company studied due to optimizing the production variety of different plants by applying general linear programming. Saedt et al (1991) developed an optimization model for transition from the firm's present production scheme towards the desired production scheme.…”