As the name implies, common data model or CIM, is a business (and technical) model of entities that are used during a telecommunication operator’s activities. As the businesses and the operational functions become complex, integrations between tools that are handling those also become complex. Telecommunications, probably the most complex business among the others has been suffering this since it’s beginnings.
In Telco, there are hundreds of entities that can be involved in a business process. And most of the time, these entities are managed by different OSS or BSS components. In order for the process to flow, two or more entities should be shared as information carriers.
The multi-vendor structure of the Telco sector introduces problems in here. The OSS/BSS vendors use entities that are conceptually same but technically different. A customer entity has a customerName attribute in one tool, the same attribute is called “cName” in the other tool. Following the same example, the first tool holds a customer type attribute in Integer type, while the other holds the same in a String type. Obviously, there should be some conversions between these two systems.
To put the understanding of these entities to a common ground, common data model studies have been around since the beginning of the sector. The aim is to simplify the inter-tool integrations. The last concrete effort on hand is the TMForum Shared Information Data Model (SID).
A common understanding requires, abstraction and abstraction means the loss of the details. We can see the loss of the details in the attributes level in the SID model for example. SID, tries to avoid common attribute names rather it tries to spread them to atomic entities. This approach makes the model involve lots of new entities.
TMForum says, SID is an informational model , not a data model , so it rather should be customized to be aligned with the organization. This alignment is done via class extensions or attribute additions. (which different vendors may decide to implement separately)
When I am designing(and developing) a brand new OSS tool, I can use this common model for sure. If the tool I will communicate in the business process uses the same entities(not customized ones), they can communicate (slightly) seamless. But is this the case? Look at the off-the-shelf tools around the Telco business. None of them implements a common information model. Some vendors offering multiple tools in the OSS domain, however implement their own propriety models to improve integration between their components but these are propriety.
Look at the big OSS vendors. Most of these vendors are not interested in this common world. They don’t have OSS/J adapters natively supported for example. They rely on small partners to provide and sell the adapters separately.
Common information model, will dramatically reduce the system integration costs which are not welcomed by these vendors. And this CIM thing will kill an argument like “Buy also TT from us, not from another vendor. Because our TT has seamless integration with our PM tool which we cannot guarantee with the other tool”.
In today’s environment, If I wrote that CIM based brand new tool, I still need to write an adapter that will do the necessary conversions and mappings on the “legacy” tool’s side. (The conversions and mappings can be implemented on the bus if I use an ESB). Even in SID-SID communications, if one side has done some “custom” things such as addition of new classes, the other side should be aligned to that change on the adapter or bus level.
In any case you will write adapters, you will do mappings, you will add validation rules. There will always be some integration effort and if you are not living in the ideal “all SID” world, your additional efforts to aligning to a CIM (SID etc.) will multiply the costs and risks.