  Without a specific functional context, non-functional requirements can only
be approached as cross-cutting concerns and treated uniformly across all
features of an application. This neglects, however, the heterogeneity of
non-functional requirements that arises from stakeholder interests and the
distinct functional scopes of software systems, which mutually influence how
these non-functional requirements have to be satisfied. Earlier studies showed
that the different types and objectives of non-functional requirements result
in either vague or unbalanced specification of non-functional requirements. We
propose a task analytic approach for eliciting and modeling user tasks to
approach the stakeholders' pursued interests towards the software product.
Stakeholder interests are structurally related to user tasks and each interest
can be specified individually as a constraint of a specific user task. These
constraints support DevOps teams with important guidance on how the interest of
the stakeholder can be satisfied in the software lifecycle sufficiently. We
propose a structured approach, intertwining task-oriented functional
requirements with non-functional stakeholder interests to specify constraints
on the level of user tasks. We also present results of a case study with domain
experts, which reveals that our task modeling and interest-tailoring method
increases the comprehensibility of non-functional requirements as well as their
impact on the functional requirements, i.e., the users' tasks.
