SAP S/4HANA

SAP is one of the best tool if your input data is proper (Garbage in - Garbage Out)
It is very easy to use the software with the help of T Codes.
Reporting is very useful. You cannot delete an entry so it is perfect for audit trails.
For repetitive you can save various layouts and variants to save time.

1. Implantation of software takes both time and money and is not suitable for early stage companies.
2. User training is another challenge since you need all the users (from Procurement to Finance to management) to learn the system and do their role perfectly
3. Customization is often costly

The best feature you cannot delete the entries once made in the system and hence it has a perfect audit log. Also over the period SAP has evolved and is taking care of flow between different modules Purchase, Sales, FA, FI & CO. You can generate various different reports with a simple T Code. You can also restrict which users can have access to which data or transaction as per your organizational needs.

I think the most complex part is customization, you really need to be very sure of what you want. Also at times you need to have skilled staff for certain critical processes as the system is works on Garbage in Garbage Out concept.

As per organization needs. You could define user role-based access in the system with solid activity Log that helps in Audit. Ease of navigating different options both with mouse clicking & T-Codes. Wide-ranging reports are extremely helpful.

It is quite an expensive ERP Solution that requires extensive prior training to go live. It also prevents to capture all countries Taxes, Duties due to its certain restriction. You also have to be very particular about its customization else it could be cumbersome.