Interconnecting systems are systems that are not primary to the business function of the project. Interconnecting systems are discussed when one business section sends information to another section or it may receive information from another business section. The following questions outline concerns that are related to interconnecting systems.
What other systems does this system connect to?
What other systems does this system depend upon?
What other data does this system depend upon being able to access?
What protocols are used to connect to the other systems or services?
Do protocols used to connect to other systems adequately protect data and does the use of them compromise the security of either system?
What process is used to send or receive data to or from other systems? (replication, scheduled batch (how often?), manual FTP, etc)
How is data formatted for sending?
How is data validated when it arrives at the receiving system? How is the receiving system sure that the source of the data is valid?
How often is data sent between the systems?
Will firewall rules be required to connect the systems? Will the required rules be allowed or will they compromise the security of the organization?
If the receiving system does not get its data, what is the effect on the business?
How is a failure of the systems' ability to connect detected and remedied?