1. COM Data Control
2. COM Data Server
3. Siebel Web Client Automation Server
4. Siebel Mobile Web Client Automation Server

The first 2 flavors are in non-UI context and the other 2 are in UI context. UI context means that there should be an instance of Siebel application running and these interfaces will use that instance to connect to Siebel. In UI context you do not have to specifically instantiate Siebel objects as you can use the currently active objects. In non-UI context you do need to specifically login to the application and instantiate objects as there are no active objects. All of these objects are not zero footprint and require specific installation of the objects on client machine. These objects are usually installed as part of Siebel EAI installation.

Let us talk about COM Data Server in more details as it is the most popular Siebel COM interface. This interface allows you to connect to a Siebel server directly from a COM compliant application and call any of the methods for Siebel Application, Business Object, Business Component, Business Service and Siebel Workflow. It is very popular method for Microsoft based technologies to connect to Siebel. You can either write a Dot Net program or a Visual Basic program to interact with Siebel. You can also interact with Siebel from MS Excel and MS Access using this interface.

It is a very popular method for allowing business users to directly inract with Siebel data from Excel spreadsheet and Excel spreadsheets tend to be a favorite with the business user community.

Pros

1. Very easy to interact with Siebel.
2. Can be used to load/query data in Siebel from Excel spreadsheet for repetitive tasks.
3. Allows you to do pretty much anything in Siebel.

Cons

1. Requires installation of the object.
2. Allows you direct access to business components which means you can bypass all the security. Siebel typically allows you to control who has access to what views and business services but not business components.

Oracle (Siebel) recommends EIM as the primary method of loading mass quantities of data into the Siebel database. You can use EIM to perform bulk imports, updates, merges, and deletes of data.

The set of tables in Siebel where the user data is stored are called Base tables. Oracle (Siebel) does not support using native SQL to manipulate data directly in the base tables. Direct SQL operations are however allowed for EIM tables. Siebel has built-in jobs that cam move data in from EIM Table to Base tables and vice versa. Loading data into Siebel Base table using the EIM process is a 2-step process:
1. Load data into EIM tables.
2. Run Siebel EIM to import the data from the EIM tables into the Siebel base tables.

There is a key difference when data is loaded through EIM Vs other options. When data is entered through the Siebel user interface (or other methods), the application references properties set at the business component object type. However, when data is entered into Siebel base tables through EIM, EIM references properties set at the table object type.

The mapping between the EIM table and base table s defined in the Siebel Tools. OOTB tables come with pre-defined EIM tables and associated mappings. If you extend the schema by adding new table and/or columns then you will have to extend the EIM tables as well along with defining/modifying the mappings. Once the data is loaded into the EIM tables, you can run the Siebel EIM job to import the data. One of the inputs to this job is a configuration file called EIM Configuration File. This file is either an ASCII or Unicode (binary) text file of extension type .IFB that resides in the Siebel Server/admin directory. It allows you to define the type of EIM processes to be performed: export, delete, merge, or import.

Pros:
1. It is fast and simple
2. Can be used repetitively for similar data loads
3. Does not require deep Siebel expertise

Cons:
1. Essentially Garbage-in Garbage-out model.
2. There are no validations based on business logic
3. Bypasses all the logic built at the Siebel object layers

1. Web Services:
   1. Outbound Web Services: Siebel applications can consume the WSDL (Web Service Description Language) document describing the service and operations, and generate a proxy Business Service allowing the Siebel Business Application to invoke the Web Services just like a local object. When the Business Service is invoked, the Object Manager detects that the Business Service is a proxy to a Web Service and generates the appropriate SOAP (Simple Object Access Protocol) message and dispatches the request using a configured transport such as HTTP.
   2. Inbound Web Services: Siebel also allows you to access a Siebel Business Service (including Workflows) as a Web Service. Unfortunately you cannot publish this web service for subscribers to discover. You will have to export the WSDL from Siebel and send it to the subscribers.
2. COM Data Server: Siebel COM Data Server allows you to connect to Siebel over TCP/IP and access Siebel objects like Business Objects, Business Components, Business Services, Workflows, etc.
3. Siebel Enterprise Integration Manager: EIM allows you to schedule high-volume data exchanges between Siebel applications and other applications. Siebel has a set of EIM tables where you are allowed to do direct SQL operations. You can move data in or out from Siebel base tables to EIM tables through Siebel jobs.
4. Siebel EAI Adapters:
   1. HTTP Adapter: Siebel HTTP Adapter is one of the Siebel EAI adapters that allow Siebel application to communicate with other applications over HTTP protocol.
   2. MQSeries Adapter: It allows Siebel to communicate with the IBM MQSeries messaging system.
   3. MSMQ Adapter: It allows Siebel application to communicate with the Microsoft MQ messaging system.
5. Java Business Service: The Java Business Service allows the sending or receiving of messages through a JMS.
6. Siebel Java Data Bean: The Java Data Bean is a collection of Java Classes that allow developers to interact with a variety of Siebel Objects such as business objects, business components, and so on. Using this interface, you can develop Java/J2EE components that interact with Siebel.

There is no one best option out of the options mentioned above. Each option has its own strengths and weaknesses. It is possible for you to create an hybrid option utilizing the strengths of 2 options while avoiding the weaknesses. I will provide more details about each of the option in the next few blogs.