Much depends upon the size of people you wish to cover for PMS. For smaller teams, there are IT companies who can customise your requirements. Your company's hierarchy levels, extent of business, so many factors need to be taken into account. Am a HR Consultant, doing the same thing, customising the PMS. Myself and my partner visited Doha, Qatar in October last for auditing a leading logistics firm and found out that many things were missing in the organisation. We then gave them a road map leading to the culmination of PMS implementation. I have come here to Doha again on 3rd January for a month's stay to look at the state of implementation plus auditing of other HR processes. My partner will join around mid-Jan. If interested, we can look at the business in detail, meet the stakeholders and suggest a cost-effective and easily operational process. We have written an article in Linkedin on our audit mission after our return from Doha. We are not an organisation but a couple of elderly senior HR professionals without any overheads. Hire us and you will not be disappointed.
Best wishes