If you designed your questionnaire correctly you have form hypotheses between relations of constructs. For example I think you have implementation success as an Y variable dependent on manager involvement.
Now, you most probably have questions in your questionnaire which measure those variables somehow.
When you have the results of your questions you can make a scale (or index for that matter) to measure your construct. You can do this by using a few methods (be sure to invert negative questions in terms of scale)
When for example you measure implementation success with 5 questions. You may take the mean of those scores (again, rescale negative questions!) assuming they have equal weights for determination of the construct. Also, you could just give them weights by guesstimates.
What's more, you could extract factor scores to have a less arbitrary weighting. All of these methods have their (dis)advantages over the others.
Checking whether questions measure the same thing can be done by using reliability (Cronbach's) alpha. But be sure to know what it does.And also be sure to use other metrics, measures, tests and a healthy dose of face validity and common sense.
Finally you investigate the relationships between your constructs (measured by your developed scales) with for example correlations or regressions.
I hope this helps, good luck!