What aspects are critical and need to be considered while moving from a manual HR process to an Oracle or SAP based system/process?

Change Management is critical.
Assuring your end users are comfortable with the automated process is key.
It doesnt work to give the end users just one or two formal training on the new system will not suffice.

3 things which are extremely important and should be always considered while implementing any system   a.
People Capability   – Open to accept new system – Learning And UN-LEARNING OR letting go age old way of working   identify people who are capable to drive the new system as well as are the users using the system are capable to reap the benefits of new system   b.
Process Maturity   – are the existing process OR New process matured enough to be aligned to new System (SAP / Oracle / any other ERP)   c.Technology Environment   – Is the current technology environment capable to handle the load of SAP / Oracle …more often than always CXOs are approve ERPs but feel over budgeted for approving other technology upgrading

One should not forget that automating processes will have cultural effects, as it is no longer possible to bypass, the system will make automatic decisions etc. In order to automate howver, the processes should me matured and NOW already followed up with discipline. Dont force the culture change through the tool, change the culture and then solidify the culture in a tool. Finally such an implementation asks a lot from time and flexibility (and frustrations) in the organization. Work to manage expectations. The tool increases efficiency AFTER implementation. Also then the question will come, what manpower now can disappear, as the process is automated.... 

Inputs and basic Conditions Social

Data Integrity, Accuracy and completeness. Also access rights and authorisation procedures.

When starting manual process automation we should observe the following points:

- Improving the workflow: find the way to simplify current procedures of how to push requests faster through approvals bottle necks.

- Notification enhancement: study well the required notification make sure not to shower users with tons of mails and alerts beyond their management capacity.

- Self-service: HR services like profile update, letters certifications pay slip prints, leave per diem and training requests, authorization and on absence delegations, all must be studied well to simplify the process and provide both management and crew a smoother HR tools.