Introduction Of course

Of course, no one thought of an issue in the same way, but the profit of the companies depends on the good management , an issue that seems to be unanimous among the leaders of the company. This is what happened here, when we try to examine and examine the past and present work that deals with inventory management and the development of an economic quantity model suitable for contractor companies. The subject of inventory management has sparked much debate in public debates, workshops and symposia, at the local, national and international levels, between public institutions and policy makers, organizations and academics. Various efforts have been made through the management of new businesses through projects, incentives, etc. For the organization of workshops in the same field. A study of most scripts in inventory management has some common and interesting features. Many of these writings deal with most of the problems associated with inventory management; others still focus on the best inventory management model.
This literature review was largely based on journals, some ,owner interview and expert opinions on issues relevant to the objectives of this study. It is divided into the following items:
1. Inventory Management Techniques
2. Re-Order Level
3. Economic Order Quantity
4. Just-In-Time.

2.1.1 Inventory management
Inventory management could be a bargains with administration of settled and current resources. Moreover, it involves the management of day by day operational supplies and in our case. Stock is additionally a basic resource in any organization in spite of the fact that agreeing to Barnes (2008) stock is looked at as a risk beneath the just-in-time (JIT) control framework. He agrees with the way accountants treat stock as an resource to the organization. Within the explanation of money related position, stock shows up beneath the current resources of the organization in any case whether it’s for benefit or not for benefit organization. Stock plays a major role and its administration goes a long way in making a difference a firm to develop because it relates to its external customers as well as the inner clients (Gibson, 2013). Therefore, stock is basic within the operation of Aref Contractor Company since they may hold stock as finished products, work in progress or raw materials for advance preparing (Fellows and Rottger (2005) and Shapiro (2009)). Shapiro, (2009) also advises that stock plays a crucial part when it comes to demand 15 planning and as a result, the organization needs to be flexible in its management of its stock when it comes to occasional or regular inventories.
Directors cannot avoid inventory management since it shapes the basis of their in general performance through disposal of uncertainties in their management. For the boards and management of Aref Contractor Company to find out that they are performing over standards, inventory management metric measures should be over board so that they may keep up the management’s certainty (Shapiro, 2009). Subsequently, Just-in-time concept has been found to have a few outlandish hidden cost that increment the cost of doing business in a few cases such as little suppliers to expansive companies .

Although inventory problems are as old as history itself, it has only been since the turn ofthe century that any attempts has been made to employ analytical techniques in studying theseproblems. The initial impetus for the use of mathematical methods in inventory analysisseems to have been supplied by the concurrent growth of the manufacturing industries andthe various branches of engineering, – especially industrial engineering. The real need foranalysis was first recognized in industries that had a combination of production schedulingproblems and inventory problems i.e. in situations in which items were produced in lots – thecost of set up being fairly high – and then stored at a factory warehouse (Ardichvili, A., Cardozo, R. and Ray, S., 2003)
The inventory system is basically an input-output system. In order toarrive at the best inventory policy i.e. the best decision rules for when and how much to order, it is necessary to have a clear picture of the inventory system.

Figure 2.1 An input-Output representation of an Inventory System.

It is system that we can proceed to analyses its operation and effectiveness
Regardless of the items in the warehouse, an inventory system requires the specification of
components shown in the entrée-sortie representation of figure 2.1; these include:
1. The mods of application for items held in stock (ie the output of the system). The ne peut pas être contrôlé, ne peut pas être contrôlé, ne peut être comparé à la plus grande request de l’inventeur.
2. The supply model (l’entrée du système). The contrôle le contrôle du inventory système.
3. Operational constraints: Generally, the range of options to make the decisions to manage a system in stock is limited by a series of restrictions related to limited stock, to the limited budgeto disponible par stocks etc. Occasionally, the pays of est origin limité à la politique des extranjeros en relation avec le nombre de valores. Unless such constraints are not taken explicitly, it is difficult to arrive at an optimal and feasible inventory policy. (Xu, Z. and Zhang, X., 2013).