Inventory Of Goods Data Processing Using The Economic Order Quantity (Eoq) Method

Sriwijaya State Polytechnic (Polsri) which is one of the State Education Institutions in South Sumatra has Diploma III and Diploma IV programs. Currently, it has 23 Study Programs from 9 majors both in the engineering and non-engineering fields. The demand for tools and materials to support activities in each department, the Center and Technical Implementation Unit (UPT) is done manually, where the department administration department records the needs needed by the department known by the head of the department. Utilize the data processing system using the EOQ method facilitates the processing of inventory data. To overcome problems in the management of goods data in the warehouse such as running out of stock when a request appears from the Department, Central, and UPT. Data processing that has been computerized takes place so it can be stored properly and easily managed. The result of this research is web-based on an inventory of goods data processing using the economic order quantity method.


Introduction
Sriwijaya State Polytechnic (Polsri) is one of the State Education Institutions in South Sumatra that has Diploma III and Diploma IV programs. Sriwijaya State Polytechnic currently has 23 (twenty-three) Study Programs from 9 (nine) majors both in the engineering and non-engineering fields. Currently the demand for tools and materials to support activities in each department, the Center and Technical Implementation Unit (UPT) is still done manually where the department administration department records the needs needed by the department and known by with the head of the department. Some forms need to be filled out and signed by the head of the department then the head of the Center and the head of the UPT give it to the police inventory section for validation. The needs of the Department, Center, and UPT will be provided if the availability of the requested equipment and materials is available.
Inventory management is the process of efficiently overseeing the constant flow of units into and out of an existing stock of goods [1]. Inventory management is a vital function to help insure the success of manufacturing and distribution companies. The effectiveness of inventory management systems is directly measurable by how successful a company is in providing high levels of customer service, low inventory investment, maximum throughput and low costs [2]. Inventory management is a complex process, particularly for bigger organizations, but the basics are same indifferent of size or type of the organizations. In inventory management, products are delivered into the acquiring area of a warehouse in the form of raw materials or components and are put into stock areas. In comparison with the bigger organizations with more available physical space, in smaller companies, the products may go directly to the stock area instead of a receiving location, and in case of wholesale distributor, the products may be prepared products rather than raw materials or components. The products are then picked from the stock areas and carried to production facilities where these are made into finished products. The finished products may be restored to stock areas where these are held prior to shipment, or these may be exported directly to consumers. Inventory management uses a variety of data and keeps track of the products as these moves through the process, including lot numbers, serial numbers, cost of products, quantity of products and the dates when these move through the process [3].
Inventory management is an activity carried out by a company that is needed in making decisions so that the need for materials or goods for the needs of company activities can be optimally met with the smallest possible risk. Inventories that are too large (overstock) are a waste because it causes too high costs for storage and maintenance costs during storage in the warehouse. This research tries to build an inventory application by applying the EOQ (Economic Order Quantity) method as a basis for development.
With the website-based goods inventory data processing in the Polsri, it is easier to process inventory data in order to overcome problems that may occur in the management of goods data in warehouses, such as running out of stock when there is a request from the Department, Center, and UPT, and processing computerized data so that the process that takes place is not complicated and the existing data can be stored properly and easily managed.

Research Methods
The Economic Order Quantity and a Reorder Point (EOQ/ROP) model have been used for many years, but yet some companies have not taken advantage of it. An Economic order quantity could assist in deciding what would be the best optimal order quantity at the company's lowest price. Similar to EOQ, the reorder point will advise when to place an order for specific products based on there historical demand. The reorder point also allows sufficient stock at hand to satisfy demand while the next order arrives due to the lead time. Since retail can be unpredictable and competitive, the interest of seeing how forecasting can affect the The process of building computer software and information systems has been always dictated by different development methodologies. A software development methodology refers to the framework that is used to plan, manage, and control the process of developing an information system. The development of this research uses the waterfall model. The Waterfall SDLC model is a sequential software development process where the progress is regarded as flowing downwards which is similar to a waterfall in nature through a list of phases that must be executed step by step in order to successfully build a computer software. Originally, the Waterfall model was proposed by Winston W. Royce in 1970 to describe a possible software engineering practice [5]. Figure 1 below shows the process waterfall model.

Figure 1. The Process of Waterfall Model
Analysis Phase: Usually named as Software Requirements Specification (SRS) is a complete and comprehensive description of the behavior of the software to be developed. It implicates system and business analysts to define both functional and non-functional requirements. Usually, functional requirements are defined by means of use cases which describe the users' interactions with the software. It includes such requirements as purpose, scope, perspective, functions, software attributes, user characteristics, functionalities specifications, interface requirements, and database requirements. In contrast, the non-functional requirements refer to the various criteria, constraints, limitations, and requirements imposed on the design and operation of the software rather than on particular behaviors. It includes such properties as reliability, scalability, testability, availability, maintainability, performance, and quality standards Design Phase: It is the process of planning and problem solving for a software solution. It implicates software developers and designers to define the plan for a solution which includes algorithm design, software architecture design, database conceptual schema and logical diagram design, concept design, graphical user interface design, and data structure definition. Implementation Phase: It refers to the realization of business requirements and design specifications into a concrete executable program, database, website, or software component through programming and deployment. This phase is where the real code is written and compiled into an operational application, and where the database and text files are created. In other words, it is the process of converting the whole requirements and blueprints into a production environment.
Testing Phase: It is also known as verification and validation which is a process for checking that a software solution meets the original requirements and specifications and that it accomplishes its intended purpose. In fact, verification is the process of evaluating software to determine whether the products of a given

The Display of Department Admin Pages
On the admin page of each majors in Polsri, you can see the amount of stock and demand for stock. The admin page can be seen in Figure 4 below.  Figure 5 below shows the item request page sent by the admin department admin. Admin enter the request for goods to be submitted by the list that has been available in each department, the proposed request will be analyzed to obtain approval from the inventory.