 
In the case you have chosen to implement best-of-breed solutions, by definition there should be no or very small functional gap in their specialty field.
However, we have identified four main issues regarding best-of-breed approach:
The second issue is the consequence of the first: because it is costly, almost no company in the world can afford a best-of-breed software for each and every specialty field. However, there will be fields where you will not be able to invest a large amount of money, but still you have to address those needs. How will you do this?
The third point is how to get heterogeneous solutions to work together: this is always a heavy, costly and long-term project in itself before you can leverage your solutions on the company level.
The last one, but not the least, is no matter how good your mix of best-of-breed solutions may be, you might be among those investment companies who need maximum complexity. In this case, more often than not, your mix of solutions will not reflect your business uniqueness.
"In a best of breed strategy,
        
The Last Mile is a combination of those four factors."