
65
3
Implementation
In order to produce results that inform a health technology assessment
(HTA), a model design must be converted into executable computer code
that performs the required calculations. Implementation refers to the actual
processes involved in taking the model from design to working software.
A discrete event simulation (DES) can, in principle, be constructed using
paper and pencil. But apart from its didactic benet, this is extremely cum-
bersome even for a very simple model and not feasible for a realistic HTA.
Fortunately, the advent of computers made it possible to carry out complex
DES, and, thus, since the 1950s there ha