The supply function has an important role to support the business to create a customer value. Two important parts of this process is to have the warehouses and production sites in the right location and to have the right items stocked at the right level.   This thesis is concerned with those two parts of the supply chain management. Three different areas of inventory control are dealt with. In the first part we consider the classical dynamic lot size problem without backlogging. The second part deals with estimation of holding and shortage costs in two-level distribution inventory systems. In the third part of the thesis we consider the localisation problem in a multi-level supply network system where items are consolidated at a warehouse and distributed to customers on routes.   Within the area of inventory control we have evaluated a method earlier suggested by Axsäter (1988), the method is evaluated using a set of test problems and compared other heuristic methods, including the well-known Silver-Meal’s method (Silver and Meal, 1973).  The result shows that the method suggested by Axsäter does perform better than the other methods. In the latest contribution we point to the important differences between Least Period Cost and Silver-Meal when several periods have zero demand. In the area of inventory control we have also studied a two-echelon inventory system where we present methods for estimating the shortage- and stockholding costs in such inventory systems.   The second part subject of the thesis concerns supply network optimization. We present a MIP formulation of the problem and evaluate in detail the approximation of the distribution cost when customers are delivered on multi-stop routes. An improved method for estimating the distribution is presented.   Besides this introductory overview five research papers are included in the thesis. The first and the last paper consider evaluation of dynamic lot sizing heuristics. The second and third paper deals with cost evaluation of a stochastic two-echelon inventory system and the forth paper with evaluation of methods for estimating distribution costs in a supply network.

Long cycle times in semiconductor manufacturing represent an increasing challenge for the industry and lead to a growing need of break-through approaches to reduce it. Small lot sizes and the conversion of batch processes to mini-batch or single-wafer processes are widely regarded as a promising means for a step-wise cycle time reduction. Our analysis with discrete-event simulation and queueing theory shows that small lot size and the replacement of batch tools with mini-batch or single wafer tools are beneficial but lot size reduction lacks persuasive effectiveness if reduced by more than half. Because the results are not completely convincing, we develop a new semiconductor tool type that further reduces cycle time by lot streaming leveraging the lot size reduction efforts. We show that this combined approach can lead to a cycle time reduction of more than 80%.

過去一般認為，土地供給是固定不變，故價格彈性為零。這樣的思考方式背後隱含需求面才是不動產市場的主導力量，因此土地供給面往往被忽略。不動產僵局的議題近年來不斷出現在世界各國，臺灣社會也不例外。由此觀之，都市住宅供給過程中，似乎不完全由市場需求面主導，尤其都市進入成熟發展階段後，土地供給面的重要程度更應該被突顯。故本研究從供給角度出發，並認為土地面積和產權在都市住宅供給過程中，可能扮演關鍵的角色。透過本研究提出之二維向度分析，也確實發現開發難度和住宅區開發量間存在一定的負向關係，為後續迴歸分析的立論基礎。市場力量或政府力量是否能克服基地面積過小和產權複雜問題，亦是本研究關注之重點。 利用臺北市民國94年到103年的使用執照和拆除執照，以里為分析單元，計算臺北市各里住宅區的樓地板面積淨增加率，並觀察其在空間上之高低分布。影響樓地板面積淨增加率的因素除包含土地面積和產權因素，亦應包括總體因素，區位與政策因素。一般迴歸模型和空間迴歸模型之實證結果顯示：各里中住宅供給多寡主要受到總體因素影響。此外，劃定都市更新地區之政策亦具有吸引建築投資之效果。然而土地面積並非是影響住宅供給之關鍵因素。但本研究進一步發現，在相同條件之下，產權單純對於住宅開發供給多寡的差異，因臺北市區位而有不同，住宅開發供給量由多至少依序為早期發展區、郊區和市中心。且在早期發展地區，產權越複雜的里比起產權較單純的里，住宅供給確實有較少的趨勢，顯示土地產權仍然在臺北市部分地區，造成開發上的問題。 / It is understood that land supply is fixed and the price elasticity is zero, which implies that the side of demand is the dominant force in the real estate market. Because of this the supply side of land is often ignored. The issues of gridlock of real estate development are emerging in recent years worldwide, and Taiwan is no exception. In these instances the market does not seem entirely dominated by demand in the process of housing supply. Especially in cities which have entered a mature stage of development, the importance of land supply should be highlighted. This study is taking the perspective of supply and considering that lot size and land property key roles in the process of housing supply. Throughout this study, we proposed a two-dimensional analysis and indeed found that there was a negative relationship between development difficulty and the amount of residential development, which was the theoretical basis for the subsequent regression analysis. Whether market force or government force can overcome the problems of small lot size and complex land property was also a focus of attention in this study. We used Building Use Permit and Demolition Permit from the year2005 to2014 in Taipei and the analysis units were individual neighborhoods. We calculate net increasing rate of floor area in residential sections of Taipei and observe its distribution in space. Factors affecting net increasing rate of floor area in residential sections include lot size and ownership factors, as well as general factors, region and policy factors. According to ordinary least squares (OLS) and spatial regression, the empirical results show that housing supply in each neighborhood in Taipei is dominated by general factors. In addition, the policy of the delineated renewal areas has the effect of attracting construction investment. However, the lot size was not a key factor in the process of housing supply. Furthermore, the study found that under simple land property conditions, housing supply discrepancies over location in Taipei and supplied quantity in order was the old core, periphery and center. And in the old core, compared to the neighborhoods of simple land property, the housing supply in neighborhoods of complex land property has a decreasing trend which reveals that land property is still causing development problems in parts of Taipei.