Common details in the acceptance criteria of related user stories

Question

I'd like to state first that I'm still learning about scrum, so my apologies if my question seemed naïve.

Lets say we have an E-learning portal, and I have the following user story:

"As a University student, I want to see my fee for the semester, so that I know the remaining balance."

I've written the following AC:

• When tuition fee page is visited, fee is calculated to the screen.
• Fee is displayed

I've omitted the a bullet point (which I had placed at the top):

- Student must be logged to the system.

Since I considered that there will be a dedicated user story for login/sign-up, and to my understanding, AC works as an end-to-end experience from the user perspective and also the development roadmap from the developer perspective. So I did that because I was concerned that one assigned developer to this story might see that bullet point and start implementing a login/sign up system, while in the meantime another developer is assigned to the login/sign-up user story and he is implementing it.

Is this way of thinking makes sense? Please correct me if I'm wrong. Note: I know that tasks will later on be given into each user story.

Answer 1

"Student must be logged to the system" on its own is a bit confusing in the context of either the fee story or the login story - is it a prerequisite or is it an outcome? For the login story, you might say something like "when a student enters their credentials, they are logged in to the system" (an outcome). For the fee story, you might say something like "when a logged-in student visits the tuition fee page, fee is calculated and displayed on the screen" (a prerequisite).

Beyond this, the level of detail in your acceptance criteria comes down to what your team is comfortable with and is something you should be continually refining through retrospectives. You might decide that your team needs more details ("... enters their username/password and clicks the Login button") or less details (everyone understands that the fee page requires you to be logged in, so you can omit this detail).

Answer 2

The story about logging in depends on the story about seeing the semester fee. This is common and unavoidable. Just make sure you set up and communicate dependencies between stories.

The reality is that both stories cannot be implemented at the same time, but you can gain concurrent work at the task level. The second story just won't pass until the login story is finished.

Sometimes you just encounter bottle necks in development.