Supply Chain Management (SCM) is the integration between manufacturer, transporter and customer in order to form one seamless chain that allows smooth flow of raw materials, information and products throughout the entire network that help in minimizing all related efforts and costs. The main objective of this paper is to develop a model that can accept a specified number of spare-parts within the supply chain, simulating its inventory operations throughout all stages in order to minimize the inventory holding costs, base-stock, safety-stock, and to find the optimum quantity of inventory levels, thereby suggesting a way forward to adapt some factors of Just-In-Time to minimizing the inventory costs throughout the entire supply chain. The model has been developed using Micro- Soft Excel & Visual Basic in order to study inventory allocations in any network of the supply chain. The application and reproducibility of this model were tested by comparing the actual system that was implemented in the case study with the results of the developed model. The findings showed that the total inventory costs of the developed model are about 50% less than the actual costs of the inventory items within the case study. arabic 14 English 67
Rajab HOKOMA, Faraj Farhat El Dabee(9-2012)

This paper investigates the current status of the implementation level of Just-In-Time (JIT) within the Oil & Gas (OGI), Iron & Steel (ISI), Cement (CI) and Construction (C) Industries within Libya and its implication for management within the said industries. A survey methodology has been applied in this investigation using an intensive questionnaire and one-to-one interviews of the correspondent organizations. Based on the analysis of the survey questionnaire and the one-to-one interview responses, the results show that the management body does not have a clear strategy towards most of the areas that are considered as being crucial in any successful implementation of the JIT techniques. The implementation levels of the JIT techniques are found to be in the modest levels even in the organizations that have indicated themselves as JIT implementers. The research has identified management limitations within the investigated areas and has pointed to areas where the management body needs to take immediate actions in order to achieve an effective and successful JIT implementation within their organizations. This is an important finding for the future success of the Libyan industries and the similar ones. arabic 18 English 107
ٌRajab HOKOMA(1-2016)

تتعرض هذه الرسالة لدراسة نظرية لنموذجين مختلفين للمجمعات الشمسية، المعدنية وغير معدنية . وذلك لتعين معاملات الأداء لهذه المجمعات مثل معامل فقد الحرارة, عوامل فقد الحرارة الكلية, الكسب الحراري, الكفاءة اليومية, واللحظية.وقد أظهرت هذه الدراسة أن المجمعات المعدنية الشمسية متفوقة من حيت معاملات الأداء على المجمعات الشمسية الغير معدنية, تحت ظروف الجريان القسري. وقد دلت هذه الدراسة أيضا على أن عوامل فقد الحرارة الكلية لكلا النموذجين تظهر تغيرا طفيفا عند التغير في معدلات التدفق. كذلك فإن معامل الفقد الحراري يعتمد بصورة كبيرة على معدل التدفق لكلا لنموذجين, عند استخدام خزانات ذات سعة صغيرة. كما تبين أيضا أن الطاقة المختزنة, في المجمعات غير المعدنية, يمكن أن يستفاد منها كطاقة حرارية مفيدة حتى بعد غياب أشعة الشمس.وقد قورنت نتائج هذه الدراسة النظرية بنتائج دراسات عملية سابقة, و وجد أن هنالك تطابقا جيدا بينهما, ما عدا تلك النتائج التي تم الحصول عليها في ساعات الصباح الباكر وساعات المساء. Abstract This thesis presents a theoretical investigation of metallic and non-metallic solar water collector models for evaluating its performance parameters. The determined parameters include heat removal factor, overall heat loss coefficients, heat gain, daily and hourly efficiencies.The present study reports that, under forced circulation test, the non-metallic collector has an inferior performance parameters when compared to that of the metallic one. It was also revealed that the overall heat loss coefficients of both collectors show weak dependence on the flow rate variations. It was also noticed that the heat removal factor for both models is more sensitive to the flow rate variations when small storage tank capacities are used.The stored energy in the non-metallic flat plate solar collector model constitutes a significant part of the useful energy, even after the diminishing of the solar intensity.Finally, a comparison of performance parameters of the theoretical and experimental studies showed good agreements for most hours of the day, except the results obtained at the early morning and late after noon hours.
نورالدين عبد الحفيظ عبود (2009)