The causes are multiple. Patchwork IT landscapes built up over years of M&A, products that require servicing for decades and all set against a backdrop of continually changing regulation. The result is a complex web of technology and processes which few people understand or can explain. Attempting radical change in this kind of environment is perilous.
The only substantive solution is to build robust models of a business which enable discrete components to be isolated, managed, measured and improved. Without these models, change will always be a lottery. With them, it becomes possible to design specialised solutions for specific functions and to combine them to deliver vastly more efficient operations.