AN INTEGRATED FRAMEWORK FOR REDUCING PRECAST FABRICATION INVENTORY

Abstract

Precast fabricators strive for business success on delivering products on time. To achieve this goal, fabricators start fabrication once they receive design information. However, this practice results in finished goods inventory which is regarded as waste. The objective of this study is to develop a framework for precast fabricators to reduce the inventory. The framework consists of three components. The first time buffer evaluation is used to avoid fabricators losing capacity by considering demand variability. The second component, due date adjustment, shifts production curve closer to erection dates to reduce inventory. The third scheduling component arranges production sequences to achieve multi-objectives using genetic algorithms. One real case is experimented to demonstrate the effectiveness of the proposed framework. The application results show that the developed framework can reduce the level of finished goods inventory without changing production resources. Santrauka Surenkamosios statybos sektorius siekia didinti verslo struktūru gebejima produktus tiekti laiku. Tokia gamyba pradedama vos gavus projektine informacija. Tačiau taip gaminant susikaupia daug gaminiu atsargu, apsunkinančiu imones veikla. Šio tyrimo tikslas ‐ sukurti sistema, kuri leistu tokias atsargas sumažinti. Sistema sudaro trys komponentai. Pirmasis komponentas padeda atsižvelgti i paklausos kitima ir išvengti per didelio gamybos pajegumu mažinimo. Šis komponentas vadinamas pirmojo pareikalavimo itakos sušvelninimu. Antrasis komponentas leidžia mažinti gamybines atsargas, gamyba priderinant prie statybos ir montavimo laiko. Trečiasis sistemos komponentas skirtas planuoti darbus, išdestant gamybos operaciju sekas pagal daugiatikslius kriterijus ir taikant genetinius algoritmus. Aprašomas praktinis pavyzdys, iliustruojantis pasiūlytosios sistemos efektyvuma. Taikymo rezultatai rodo, kad igyvendinta sistema leis sumažinti pagamintos produkcijos atsargas, nemažinant gamybos sanaudu.