I recently carried out a Single instance review for one of my clients and wanted to share my thoughts for further insights/feedback from SDN comunity. As part of my review came out with a list of pros and cons for doing the same. I have listed them as tangible/untangible benefits and risks. Would love to hear back from experts who may have done similar analysis.
Single Instance – Benefits & Risks
Benefits
Tangible Benefits
· A single instance provides important benefits, including the reduction of infrastructure complexity and the standardization of processes and data.
· There is flexibility to add new business units
· Offers ease of business transactions between legal entities
· Flexibility to add, merge or divest business units as organization grows and changes · Integrated information across legal entities
· No need to implement ALE transactions between multiple instances to allow business transactions between legal entities. Thus reducing software complexity as well as cost of implementation and maintenance.
· A reduction of the Total Cost of Ownership, simplification of the IT system architecture, and helps achieve global business process harmonization.
· No need for numerous interfaces between separate SAP instances, which is a nightmare for standardization and as well as expensive to maintain
Intangible Benefits
· Single Instance forces a more disciplined approach to business process which in turn results in more reliable information.
· Results in greater efficiency and effectiveness in our day-to-day business operations
· Single instance helps underline "global template" philosophy
· Multiple SAP instances, whether in different countries, locations, or divisions, are difficult and costly to support.
· Companies with fairly straightforward business processes without a lot of specialization are good candidates for a single-instance project.
· A well-designed change control framework and appropriate support tools can help you mitigate risks associated with changes to system configuration and development.
Risks
Tangible Risk
· There is a risk of total system outage for all business units. This can be mitigated with use of UPS system
· Reduced application data security because data can be accessed across various company codes
· A change a control process that is too complex can lead to a loss of business agility
· New changes to be implemented will require approval from Change manager. This can slow down new business requirements implementation.
· Bigger user change management effort to upgrade single instance
· Bigger risk (more users affected) each time you upgrade
Intangible Risk
· Centralized single system places a much higher importance on having the appropriate change control processes in place.
· Transaction response time from overseas sites
· Time zone conflict of system resources (example Europe overnight batch transactions during US day time transactions)
. The transition from multiple instances to a single instance is a complex process.
