One of the challenges with HR and IT systems is that, left unchecked, complexity drives up operating costs and decreases agility. To be able to support the business, HR and IT have to be cost-effective and agile; otherwise how can they be taken as serious business partners within an organization? How does that complexity happen and what can you do about it?
There is an interesting interplay here between HR-type and IT-types. Of course I am generalizing, but HR-types like to design processes and policies that make people happy to work at the company; they want to please everyone by offering all sorts of compensation and benefit options for various subsets of the employee population. IT-types love to solve problems, and are often excited to be able to solve a compensation or benefits requirement with some customized configuration or coding. Or maybe even a whole new system.
As time goes by, your HRIS ends up getting some very specific things programmed or configured into it. Those things start relying on each other, and pretty soon you've constructed something that requires a lot of maintenance, and a lot of effort to change. Does this sound familiar?
Side-note: I know of some companies who implemented SAP HR in the late-90's who cursed the inflexibility of their old system and praised the features and flexibility of their new SAP HR system. As time passed, they built more custom complexity into their SAP HR system, and now they struggle with upgrades and adding new functionality to support changes in the business environment. This is not an SAP problem, or a problem with on-premise vs. SAAS; it's a management problem.
Companies can counteract the drive to complexity with an equally strong drive to simplification. Are all those compensation and benefits options really needed? What is the business benefit for each of them? Does IT have to create custom programming or configuration to support each of those options? Or, can the HR group manage those smaller options themselves, perhaps outside the system? What is the business benefit to automating them?
Question the business need for complexity, and share the benefits of simplicity.