By now, you should have a good understanding what it takes to engineer complete and correct requirements, secure design and secure code.
You are also exposed to process improvement techniques. Now you are in a good position to analyze or critique systems that have failed in the past.
Search the web for an example(s) of software development projects which failed. There will be many. Pick one which interests you. Briefly post your summary of the failed project. Be sure to touch up on the following points:
Why did it fail? Was it poor requirements, poor design, poor coding and poor testing, validation & verification?
Did it fail because of project and program management?
Did it follow good assurance techniques?
Did the project pay attention to secure design and coding?