  Various medical and surgical units operate in a typical hospital and to treat
their patients these units compete for infrastructure like operating rooms (OR)
and ward beds. How that competition is regulated affects the capacity and
output of a hospital. This article considers the impact of treating different
patient case mix (PCM) in a hospital. As each case mix has an economic
consequence and a unique profile of hospital resource usage, this consideration
is important. To better understand the case mix landscape and to identify those
which are optimal from a capacity utilisation perspective, an improved
multicriteria optimization (MCO) approach is proposed. As there are many
patient types in a typical hospital, the task of generating an archive of
non-dominated (i.e., Pareto optimal) case mix is computationally challenging.
To generate a better archive, an improved parallelised epsilon constraint
method (ECM) is introduced. Our parallel random corrective approach is
significantly faster than prior methods and is not restricted to evaluating
points on a structured uniform mesh. As such we can generate more solutions.
The application of KD-Trees is another new contribution. We use them to perform
proximity testing and to store the high dimensional Pareto frontier (PF). For
generating, viewing, navigating, and querying an archive, the development of a
suitable decision support tool (DST) is proposed and demonstrated.
