Hey @ima​ ​! Oséas here from the Customer Support Specialist team 🕵️

"Has viewed the tour" means that the user have initiated the tour while "Has completed the tour" means that the user not only viewed it but also completed it by reaching the last step of the tour.

Regarding your other question, "Has encountered failure" means that the user has experienced issues while viewing the tour where some of the elements this tour points to weren't found on your website, so this user only saw part of your tour. Therefore, is not possible that someone who has experienced any failure has also completed the tour. You can find more details on tour failures in this article.