# Introduction anaging supply chain managing is the process of planning, implementing and controlling all activities in the supply chain in the most efficient way possible. According to Bahree (2006) the supply chain includes all transfers of physical suppliers and services required to produce and value the goods and bring them to final consumer. Given the transfer of market's power to customers, meeting customer's demands not only involves producers but also the whole supply chain (SC) (Gunasekaran and Ngai, 2004). Agility in supply chain management (SCM), namely, quick, high-quality and low-cost responding to demands, reducing the product life cycle, increasing products variety, etc. is essential to the survival and development of SC members (Hanafizadeh and Sherkat, 2009). Excellence in managing supply chains is directly linked to superior organizational performance (Christopher M., 2005). There exists a contradiction among experts on differences in supply chain management and logistics. Few expetrs say both are synonymous terms, while others claim that these are two different terms. The objective of supply chains can be broken down into: end-user satisfaction, chain efficiency and supplier chain flexibility. Successful supply chain management must result in improvements in business areas. Supply chain management is focused on: increasing profits, better exploiting resources and reducing costs. Primarily the focus of supply chain is end-user satisfaction (Sharp et al., 2006). The end customer is the only one who injects "existing" money that drives the activity chain across all partners. The money is divided into chain members in proportion to its added value (Bartling, B., 2003). Supply chains are related associations of individual businesses. The concept of the network indicates the introduction of coordination in processes and relationships. An uplink means that it goes "in the opposite direction" and refers to the link between the company and its suppliers, as well as sub-suppliers with suppliers. Downstream links, or "in the direction of movement", refer to the businessto-consumer relationship (Epstein, 2006). Combined upstream and downstream connections may occur, as in the case with businesses that have return containers, pallets or internal exchange products. The flow strategy of materials, information and value streams includes: reducing the level of production breakdown (ideally just one installation step), increasing the flexibility of production assets capacity, increasing the degree of flexibility human resources capacity, greater involvement of suppliers in the production process, designing simple and short flows of information and materials, introduction of efficient information systems. Planning goals for inland transport within a part of the supply chain in production. Figure 1 presents Fixed orderquantity Model, where Optimal use: minimal transport costs, minimal idle times, high functionality and time utilization. High level of service: short waiting time, short transportation time. High flexibility: wide range of cargo for transportation, easy adaptability to the work environment. High transparency: information on the current situation, calculation of costs, establishment of indicators. Under such circumstances, in order to ensure growth, the retail supply chain must be adaptive and responsive (Ramesh, Banwet, & Shankar, 2008). Trends in production structure: production according to market needs, very limited number of products, customization to customer needs and requirements, acceptance of how fast development in new products and to quickly adapt the product range. Organizing cost-effective production also includes outsourcing capabilities, simpler means of production can be combined more easily Close (2006). In addition to the customers' orders which, generally speaking, draw a final product out of the supply chain network (pull factors), supply chain networks are often subject to push factors which are caused by the feeding of raw material into the supply chain by suppliers (push factors) (Hinkelman, 2005). # II. # Review of Literature Supply chain optimization aims to successfully control the various elements within the chain. By elements we mean participants, their external contacts, but also the way of organizing some internal activities. The essence of the optimization process is the elimination of those elements that do not create or support value, but which still exist as participants or activities within the chain. Optimization is the management of complicated supply chains in their entirety by synchronizing all value-added elements within production or distribution, while eliminating all other elements Rabbinob et al. ( 2004). In van der Vorst et al. (2000), a DES facilitates the evaluation of supply chain scenarios of a food supplier. The results obtained from the simulations suggest ways to improve the supply chain by changing inventory strategies. Based on the above definition, it can be said that there are a number of goals that firms want to achieve by optimizing the supply chain: synchronization of all elements (participants and activities) that add value in production or distribution and elimination of elements do not create or support value. In addition to the above two basic, there are some other secondary goals of supply chain optimization: providing the highest quality customer service and retaining them. Top performers have a clear supply chain strategy aligned with overall business objectives and customer requirements (Geary and Zonnenberg, 2000). The overall productivity of the supply chain can be expressed through a simple relationship between total outputs and total inputs. Globalization, market instability, reducing product lifecycles and ever increasing competition are few of the major convincing factors which are compelling companies to focus on their core competencies and outsource an increasing amount of their other nonvalue-adding activities (Prahalad & Krishnan, 2008). As mentioned earlier that performance measures in a supply chain are required "to streamline the flow of material, information, and cash, simplify the decision-making procedures, and eliminate non-value adding activities" (Gunasekaran, Patel, & Tirtiroglu, 2001). According to Bozon (2006). most of the activities in the chain are about 95% represented by non-value elements. According to them all time-related non-value activities can be classified into the following categories: queues (time until material is processed), production overhauls (bug fixes), managerial incompetence (failure to make decisions on time) and inventory costs in the supply chain. # a) Supply Chain Optimization Factors New information technologies, increasing pressure from customers on responsiveness and reliability and the globalization of operations and markets, supply chain management has become a challenge and an opportunity (Bowersox and Closs, 1996). Optimization as a process does not happen by itself. Reviewing the literature in this field, the following factors have been identified as the most important. Bento (2003) highlights three major sources of supplychain uncertainty: suppliers' failure to deliver on promises, manufacturing plant failures and computer errors, uncertainty about order quantities and the appearance of a whiplash effect. All the factors mentioned increase the volume of inventories (Miller. 2004). The very purpose of stock existence is precisely to insure against supply uncertainty. Lai, Ngai, & Cheng, (2002) distinguish three dimensions of supply chain performance in transport logistics: first, service effectiveness for shippers; second, Operational efficiency; and third, service effectiveness for consignees. Collaboration and integration of participants in the chain. Optimization is most likely to be achieved through a collaborative exchange of information between cross-functional teams within and outside the organization (Gold, 2006). Comparison with best practice. Boyles and Melvin (2005) points out that this is a thorough analysis of the success and dissemination of learning across an organization. The desire to optimize the supply chain and achieve world-class MLS must be conceptualized or have the support of top management of the company. This requires the existence of two-way communication between the management and senior managers in charge of integrating the supply chain, as well as the functions and processes within it (Frank, R. H, 2006). # III. # Methodology A set of variables that signify the impact of real working of the supply chains based on the profitability of the entire system are used to measure supply chain performance (Ramdas & Spekman, 2000). Time series methods are based on a series of data that are equally spaced in time daily, weekly, monthly, etc. data. Predicting a time series of data assumes that future values are predicted solely on historical data (Shahid & Sattar, 2017) and that other variables, no matter how potentially important data may be overlooked. By decomposing historical data, four major components of the time series can be identified Chu (2004): The figure 1 presents Fixed order-quantity Model, the decision rule, in a system of continuous inventory control with predetermined and fixed quantities of Q, is: Continuously monitor inventories (available and ordered). When supplies fall to the reorder point R, a fixed quantity of Q is ordered. If Q is fixed and demand is variable, the time between two orders will also be variable. The fixed order quantity model is also called the Q model. The fixed ordering model, in a continuous inventory control system, is fully determined by two parameters: R and Q. The order quantity Q can be approximated by the EOQ model with acceptable accuracy provided that demand variability is within acceptable limits (Demand Variability Coefficient is less than 0.2). Average demand is used to calculate Q over the EOQ formula. The reorder point (R) can be determined either on the basis of inventory cost (if known) or on the level of service. According to the basic assumptions of the EOQ model, demand and delivery times are known and constant and inventory is not exhausted. ? Trend ? Seasonal oscillations ? Cycles ? A random factor If the demand or delivery time is stochastic, then stocks may be depleted: ? In cases where demand is higher than expected. ? In cases where the delivery time is longer than expected. Determining the optimal point R, or optimal preventive (safety) stocks is possible if the unit cost of holding the stock and the unit cost of stock shortage are known. The preventative amount of inventories depends on the costs incurred in the event of inventory depletion and the cost of holding excess inventories (Hoffman, 2004). The procedure to calculate the cost is; ? For different levels of security stocks, the additional cost of holding inventory and the cost of inventory shortage are calculated. ? The amount of security stock that results in the minimum total cost is the optimal amount. The cost of holding additional inventories can be calculated as follows: Supplemental Inventory Cost = Security Inventory x Unit Annual Inventory Cost??????????.equation-1 The cost of inventory depletion can be calculated as follows: Cost of non-availability of product in stock (Quantity of product whose demand cannot be met) x (probability of demand te = quantity of product) x (unit cost of product shortage) x # Findings Brown & Dant (2008) supply chain management is in fact vital for retail success. The eyewear retailer has decided that the order point of a particular type of frame should be 50 pieces. The annual cost of holding the stock apiece is $ 5, and the lost profit in the event of inventory depletion is $ 40 per box. The store manager has experience on the likelihood of demand for frames at the time of delivery. The optimum number of orders in a year is 6. How much preventative amount should be kept in stock? The goal is to find a preventative amount that will minimize the sum of the cost of keeping an extra amount of product in stock and the cost of product shortage. The annual cost of inventory preventive supplies is equal to the cost of storing the product unit times the product number. If the preventative quantity is 20 frames and the order point is 50 frames, taking the preventive amount into account the new order point is 50 + 20 = 70 frames and this results in an increase in storage costs by 20 x $ 5 = $ 100. Depletion losses on inventories can be calculated for each preventive amount (based on a formula already known). For example, if the preventative quantity equals zero and the demand for frames during the waiting period of delivery equals 60 pieces, then the sale of 10 frames is lost since ROP = 50. In case of demand of 70, the lost sales will be 20 frames. Thus, the costs due to zero amount of preventative supplies are: Cost of non-existent product on stock = (10) (0.2) ($ 40) (6) + (20) (0.1) ($ 40) (6) = $ 960 V. # Conclusion Each prediction method brings better planning for the production or sale of other parts of the supply chain within the company. No part of the SCM can be ideally optimized if the previous one is not in this state, so every part of the supply chain, from the initial part to the end customer needs to be optimized. Each optimization brings a new loss reduction and profit increase, so you need to choose the right method to predict the needs of the company. The Q model is one of the most used methods within supply chain optimization that is why we introduced it in the study. # a) Research Implications This study has the following practical implication ? The findings of the study can be used to improve the service levels to customers while reducing overall supply chain costs." Put another way, supply chain management (SCM) involves the production, shipment and distribution of products. ? The findings of the study has the power to boost customer service, reduce operating costs and improve the financial standing of a company. Organizations increasingly find that they must rely on effective supply chains, or networks, to compete in the global market and networked economy. ? Supply-chain optimization addresses the general supply-chain problem of delivering products to customers at the lowest total cost and highest profit, trading off the costs of inventory, transportation, distributing and manufacturing. ? The finding of this study contributes to the existing body of knowledge about Supply-chain optimization, it effects on operational performance and measures to improve the lead-times. ? The study finding will help the top management of firms to formulate efficient Supply-chain strategy that can enhance the organizational operational efficiency as well as industry outcomes. ? The industry can get a competitive advantage over its competitors by lowering down the overall industry lead-time. ? The findings of the study also help in efficient inventory management system, smooth information flow, and timely availability of required raw materials and optimization of the whole supply chain, which can increase operational performance. # b) Research Limitation This study has the following Limitations ? The study is limited to the supplier's lead time and product characteristics ? The study has not explained behavioral factors related to employees and manager's personality, attitudes, and experience levels. ? Organizational composition, size, and business nature of the firm is also excluded from this research study. ? There is also limited amount of field research due to time constraints. ? Marketing, sales and other stakeholders which plays an important role in speed-to-market of a product or service are not considered in this study. 1![Figure 1: Fixed order-quantity Model](image-2.png "Figure 1 :") ![???????...............................................equation-1 IV.](image-3.png "") © 20 0 Global Journals © 2020 Global Journals ( )G Supply Chain Management, Optimization and Forecasting Techniques © 20 0 Global Journals 2 * Investment by Oil Industry Stalls BBahree The Wall Street Journal. A11 2006 * The Catalyst to Virtualization: Virtual Consolidation BBartling Journal of Petroleum Technology 2003 * Supply-Chain Logistics Reduce Costs JBento Journal of Petroleum Technology 2003 * DJBowersox DJCloss OKHelferich Logistical management New York McGraw-hill 1996 6 * Microeconomics, 6th Ed WBoyles MMelvin 2005 Houghton Mifflin Company * Uncertainty and Volatility in Today"s Energy System: Stability, Security, and Sustainability through Mutual Interdependence IBozon Journal of Petroleum Technology 2006 * On What Makes a Significant Contribution to the Retailing Literature JRBrown RDant Journal of Retailing 84 2 2008a * Managing Supply Chains: Lessons from Simulation Studies EChu California Journal of Operations Management 2 1 2004 * Logistics & Supply Chain Management: Creating Value-Adding Networks MChristopher 2005 Prentice-Hall * Building the High-Performance E & P Company DClose Journal of Petroleum Technology 2006 * National Contracts. Teaching Hypotheticals. Barbri Bar Review DGEpstein 2006 CICW * Cash-tocash: the new supply chain management metric IIFarris MTHutchison PD International Journal of Physical Distribution & Logistics Management 32 4 2002 * Microeconomics and Behavior, 6th Ed RFrank 2006 McGraw-Hill Irwin * Going Deep. Energy Companies Are Finding New Opportunities in Old Rocks RGold The Wall Street Journal 2006 * Information systems in supply chain integration and management AGunasekaran EWNgai European journal of operational research 159 2 2004 * What it means to be best in class. Supply chain management review SGeary JPZonnenberg 2000. JULY/AUG. 2000 ILL * Designing fuzzy-genetic learner model based on multi-agent systems in supply chain management PHanafizadeh MHSherkat Expert Systems with Applications 36 6 2009 * Glossary of International Trade EGHinkelman 2010 World Trade Press * Integrated Tubular-Supply-Chain Management Reduces Cost BHoffman Journal of Petroleum Technology 2004 * Measures for evaluating supply chain performance in transport logistics KHLai ETNgai TECheng Transp Res Part E 38 2002 * Economics Today -The Micro View, 12th Ed RMiller M 2004 Pearson Addison Wesley * The new age of innovation CKPrahalad MSKrishnan 2008 McGraw-Hill Professional Publishing * Optimizing the Organizational Design of a Typical Upstream Exploration and Production Company HRabbino CDunham JRitchie-Dunham Journal of Petroleum Technology 2004 * Chain or Shackles: Understanding What Drives Supply-Chain Performance. Interfaces KRamdas RESpekman 2000 30 * ARamesh DKBanwet RShankar 2008 * Modeling the enablers of supply chain collaboration International Journal of Logistics Systems and Management * Behavior of calendar anomalies, market conditions and adaptive market hypothesis: evidence from Pakistan stock exchange MNShahid ASattar Pakistan Journal of Commerce and Social Sciences (PJCSS) 11 2 2017 * Economics of Social Issues AMSharp CARegister PGrimes 2006 McGraw-Hill Irwin 13th Ed * Modelling and simulating multi-echelon food systems JGVan Der Vorst AJBeulens PVan Beek European Journal of Operational Research 122 2 2000