With the release of BPM12c, a new feature to use Business Parameters is introduced through which we can define a business parameter which will behave as a global variable which can be used within BPM project. Business Administrator can be the one responsible to modify the business parameters value dynamically at run-time which may bring change in BPM process flow where it is used.
This feature was a part of BPM10g product and was extensively used. In BPM11g, this feature is not present currently.
Business Parameters can be defined in 2 ways:

1. Using Jdev to define business parameters, and 
2. Using BPM workspace to define business parameters.

It is important to note that business parameters need to be mapped with a valid organisation unit defined in a BPM project. If the same is not handled, exceptions like 'BPM-70702' will be thrown by BPM Engine. This is because business parameters work along with organisation defined in a BPM project.

At the same time, we can use same business parameter across different organisation units with different values. Business Parameters in BPM12c has this capability to handle multiple values with different organisation units defined in a single BPM project. This enables business to re-use same business parameters defined in a BPM project across different organisations.

Business parameters can be defined using the below data types:
1. int
2. string 
3. boolean
4. double

While defining an business parameter, it is mandatory to provide a default value.

Below are the steps to define a business parameter in Jdev:

Step 1:  Open 'Organization' and click on 'Business Parameters' tab.
Step 2:  Click on '+' button.
Step 3: Add business parameter name, type and provide default value(mandatory).
Step 4: Click on 'OK' button.
Step 5: Business parameter is defined.

Below are the steps to define a business parameter in BPM workspace:

Step 1: Login to BPM workspace using admin-username and password.
Step 2: Click on 'Administration' on the right top side of workspace.
Step 3: Click on 'Business Parameters' in the left navigation panel under 'Organization'. 
Step 4:  Click on '+' button.
Step 5: Add business parameter name, type and provide default value(mandatory).
Step 6: Click on 'OK' button.
Step 7: Business parameter is defined.

Note: As told earlier in the blog, it is necessary to define and map a valid organization ID with predefined variable 'organizationalUnit' under data associations in an BPM process before the business parameter is used.

I have created one sample PoC demonstrating the use of Business Parameters in BPM12c and it can be found here.