  We consider a project that consists of a set of activities performed in
parallel under constraints on their start and finish times, including
start-finish precedence relationships, release start times, release end times,
and deadlines. The problems of interest are to decide on the optimal schedule
of the activities to minimize both the maximum flow-time over all activities,
and the project makespan. We formulate these problems as bi-objective
optimization problems in the framework of tropical mathematics which
investigates the theory and applications of algebraic systems with idempotent
operations and has various applications in management science and operations
research. Then, the use of methods and techniques of tropical optimization
allows to derive complete Pareto-optimal solutions of the problems in a direct
explicit form ready for further analysis and straightforward computation. We
discuss the computational complexity of the solution and give illustrative
examples.
