  This study is a sequel to a previous study entitled Thinging for Software
Engineers, which showed that the notion of thing, in contrast to
objectification, has some beneficial orientations in modeling. The
incorporation of thinging in conceptual modeling is required to explain the
roots of Heidegger s conception of things. This requires an understanding of
Heidegger s existential ontology to identify any relationship to thinging. This
paper is an exploration of existential ontology in search of further
clarification of the concept of thinging. We start by reviewing the thinging
machine (TM) introduced in Thinging for Software Engineers and provide a full
example of its utilization in modeling an ordering system. We follow this with
a discussion of the being (existence) of things in the word and Heidegger s
interpretation of time as a possible horizon for any understanding whatsoever
of being. We emphasize that the TM is not related directly to the Heideggerian
notion of existence and its elaborate analysis of Dasein. However, there may be
some benefit to studying non-Dasein things to provide a philosophical
foundation to thinging, as utilized in TM modeling. Interestingly, the TM can
be utilized to model existential ontology, thus increasing the level of
understanding about them.
