Hi Sueliu!
Issue tracking system is not a product related soup, its a non product SOUP (but it also could not be a SOUP in case you inhouse developed under the same SDLC as you have for the MD) in my understanding.

But we can move away from the dinner table and simple say product SW or non product SW.
What type of validation you have done for this type of SOUP?
For issue tracking system GAMP is a good guide and it also has been referenced in the ISO/TR14969:2004 (for ISO13485:2003) in chapter 7.5.2.1.3.
It is important to know, for ISO13485 certification there is no defined expectation about the extent of the validation of softwares subject to validation, only in FDA world we have and those are much more coming from process validation principles.
Moreover in ISO13485 only SWs are subject to 7.5.2.1 and 7.6 should be validated (almost anyhow

)
In case you subject to Food Drug and Cosmetic Act (like my firm does) than you should comply with the requirements given for software validation by FDA, including several guidance and (of course if applicable) the requirements set forth in part11.
For issue tracking system we have clearquest, its a customizable OTS and as such it is around category 4 as long as I can recall in GAMP4, requires user and system level requirements and verification including IQ/OQ/PQ categorization and in case there is no paper based register (we do not), part11 should be applied.
Validation based on FDA's guidance on OTS validation, assessment on Part 11 compliance, or a combination of both?
Okay

The FDA guidance for OTS,
this:
http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/ucm073778.htm
,
is not applicable to issue tracking system, because it is not part of the medical device, it is part of the automation of the QMS system and part of the automation of the process defined in 21CFR820.
What are directly applicable are the followings:
General Principles of Software Validation; Final Guidance for Industry and FDA Staff
http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/ucm085281.htm
820.70(i)
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=820.70
part11
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=11&showFR=1
Part 11, Electronic Records; Electronic Signatures — Scope and Application
http://www.fda.gov/RegulatoryInformation/Guidances/ucm125067.htm
I have a feeling that our ISO notified body does not care Part 11 compliance.
ISO notified bodies are simple not caring about part11, because it is for FDA, not for EU registration.
We may closer than far
Regards
Sz.