Data replication
In this situation, each company has exactly the same data, but each company has a unique copy of the data. The same piece of data exists in multiple (physical) places: multiple instances of the same data. The process to copy the data is called data replication.
Data replication can be carried out by database table, by record, and by column. In the first case, the entire table is being shared. In the second and the third case, portions of a table are replicated between companies or databases. This situation assumes that the update of data is controlled to ensure appropriate consistency. Because reasons for sharing data vary, these examples illustrate this concept:
Example 1: General Item Data (tcibd001)
An item is manufactured in one company and sold to an assembly company. The item number and other item data can be identical in both companies, but some data, such as the supply source, must be specified separately in each company.
If the item type is Product, the supply source of the item can be Job Shop in the manufacturing company and Purchase in the assembly company. The other item data is identical, therefore it can be specified in the manufacturing company and replicated to the assembly company.
If item type Product is not used, the item type is Manufactured in the manufacturing company and Purchased in the assembly company. The other item data can be specified in the manufacturing company and replicated to the assembly company.
Example 2: General Item Data (tcibd001)
In this example, the purchase contracts for all items are centrally controlled in one company, but other companies purchase the items. In this case, the contracts company enters all data for purchased items, and then replicates the data to the company that purchases the items. Not each purchasing company needs to have the entire item file, but only the portion that the purchasing company purchases, while the contracts company has all purchased items.