The basic principle of ERP
ERP is a huge information management system, in order to understand ERP principles, four main stages we must first develop along the first ERP, start from the most basic principles of the sixties period style MRP
We all know that, according to different sources of demand within the enterprise of materials can be divided into independent requirements and related needs two types. Independent demand is demand and external demand time is determined by business needs, such as customer orders, needs research trial samples Repairs needed spare parts; demand is related to the structure of the relationship between the material composition demand demand independent requirements material produced, for example, semi-finished products, parts, materials, etc.
The basic task of MRP
- Export-related materials (raw materials, components, etc.) from the final production plan (independent demand) demand and needs time (related needs);
- To determine the start of production (order) of time according to the needs of time and material production (order) cycle. MRP is the basic content of the preparation part of production planning and procurement plans. However, to properly prepare the part program, you must first implement the product schedule, with the term MRP II is the master production schedule (master production schedule, MPS), which is based on the MRP expanded. MRP also needs to know the parts of the product structure and BOM (Bill Of Material, BOM), in order to master production plan to start parts program; at the same time, we must know the number of stocks in order to accurately calculate the number of purchased parts, and therefore, the basic of ERP based on: (1): master production Schedule (MPS); (2) bill of materials (BOM); (3) inventory information, logical flow between their relationship shown below
MEP basic structure
Master Production Schedule (Master Production Schedule, referred to as MPS)
Master production schedule is to determine the final plan for each specific product number in each specific time. Here's the final product means for businesses finalized, the finished product to the factory, it should be specific to the product variety, type. Here's the specific time period, usually a week as a unit, in some cases, it can be days, ten days, months. Master Production Schedule detailed provisions of what is produced, what time of output, it is independent requirements planning. Master production scheduling based on customer contracts and market forecasts, the business plan or outline the production of concrete products, making it the main basis for expanded material requirements, it has played a role in the transition from the nexus comprehensive plan to specific plans.
Product Structure and BOM (Bill Of Material, BOM)
MRP system to correctly calculate the amount of time and material requirements, in particular the amount and timing of demand-related materials, first of all enable the system to know the product structure and all materials to be used in manufacturing enterprises. Finished product or structure constituted by listing all of the fitting parts, components, parts and the like, and the relationship between the number of assembly requirements. It is the basis of MRP unbundled product. For example, the figure is greatly simplified product structure of the bicycle, which generally reflects the configuration of the bicycle:
Of course, this is not what we ultimately want BOM, in order to facilitate computer identification, must take the product structure is converted into a standard data format, the data format specification document is to describe the product BOM structure. It must manifest a variety of material composition structure relationship between the number and material requirements of each component (components), the lower table is a simple product corresponding to the bicycle
BOM for the bicycle product
| level | Item number | Material name | unit | Quantity | Types of | Yield | ABC code | effective date | Lead |
|---|---|---|---|---|---|---|---|---|---|
| 0 | CB950 | bicycle | Vehicles | 1 | M | 1.0 | A | 950101 | 971231 |
| 1 | CB120 | Frame | Matter | 1 | M | 1.0 | A | 950101 | 971231 |
| 1 | CL120 | wheel | More | 2 | M | 1.0 | A | 000000 | 999999 |
| 2 | LG300 | Rims | Matter | 1 | B | 1.0 | A | 950101 | 971231 |
| 2 | LT123 | Tire | set | 1 | B | 1.0 | B | 000000 | 999999 |
| 2 | GBA30 | Spokes | root | 42 | B | 0.9 | B | 950101 | 971231 |
| 1 | 113000 | handlebar | set | 1 | B | 1.0 | A | 000000 | 999999 |
Note: Type "M" is made pieces, "B" is the outer member
Inventory
Whole inventory information is stored products, parts, database products, raw materials and other states of existence. In MRP systems, products, parts, work in process, raw materials and even tooling tools collectively referred to as materials or items. In order to facilitate computer recognition, the material must be encoded. Material identification code is unique material identification MRP system.
- Existing inventory: it refers to the material in the company warehouse to store the actual number of available inventory
- Plan receive the amount (the amount in transit): is being performed in accordance with purchase orders or production orders, at some future time the number of materials that will be put in storage or will be completed
- Assigned amount: it refers to the quantity of material stored in the warehouse but has been assigned to the
- Lead: is a task execution time consumed by the start to finish
- Order (production) batch: Supplier order or require production facilities to the production of a material within a certain period of time the number of
- Safety stock: the need to prevent or unpredictable fluctuations in supply-side, often in the warehouse should be kept as a minimum quantity to inventory safety stock
According to the above values can be calculated net demand for an item of material: Net demand = demand + gross amount of allocated - planned amount received - existing stocks