According to the BABOK® V3 Guide, the purpose of assessing the solution limitations is "to determine the factors internal to the solution that restricts the full realization of value."

The tasks of assessing solution limitations and assessing enterprise limitations are similar in nature and can be performed at the same time. Assessing solution limitations looks at internal factors that may limit the solution's ability to deliver value, whereas assessing enterprise limitations looks at factors that are external to the solution but limit its ability to deliver value.

It is the business analyst's role to assess both the internal and external factors that have an impact on the solution's ability to deliver the expected value. Regardless of when this assessment is performed during the life cycle, the activities for internal and external factor assessments are similar and involve the same considerations.

Let's consider a real-world example: 

A new online e-commerce solution has been implemented for a global shoe company. After the implementation of the e-commerce store, the performance was measured for a few months and the actual value was far below the expected value. The business analyst looked at this variance closely and noticed that it was specifically the total amount of international sales that had decreased substantially. After further investigation, the business analyst discovered that the solution didn't have the capability to change the currency of the shopping cart when dealing with different countries' customers. This resulted in a lot of abandoned carts and missed revenue from international sales. This was deemed an internal solution limitation that prevented the solution from realizing its full business value potential.