Information systems are tools. Roughly speaking, there are two perspectives — to be combined of course, for optimal practical results — from which to improve the quality of a tool. The (most) traditional perspective relies on improvements in technology for construction and operations, thus leaving requirements — and how they have been arrived at — (largely) unquestioned.
The other way leading to an improved tool is to first concentrate on requirements. Central to requirements for an information system is a so-called conceptual information model. The pertinent (research) question becomes: How can such models be improved?
Underlying the activity of conceptual information modeling are assumptions. Taken together, such assumptions, or conceptual grounds, constitute an ontology. The very first step is to recognize that different ontologies are possible. The next step is to undertake an ontological design, i.e., to create an ontology with the express purpose of improving support of modeling.
The treatise Semiosis & Sign Exchange develops an ontology that supports the conceptual variety needed for designing 'realistic' models. Next, improved construction models and, subsequently, improved tools for increasingly complex human involvement with business processes may be constructed.
The main ingredients are  Charles S. Peirce's triadic dynamics of semiosis (object-sign-interpretant) together with a triple development of his singular notion of ground,  Arthur Schopenhauer's concepts of the will, of the intellect as an instrument of a unique objectification of the will (read: an individual), of the individual's capacity for empathy and of modes of causation (according to which a sign counts as a cause aimed at a motivationally induced effect), and  the author's own modeling approach called metapattern, according to which every situation is a function of related objects and an object may exhibit different behaviors as pertaining to corresponding situations.
Combining  and  yields an enneadic, rather than a triadic, schema for semiosis. The explanatory power of a synthesis of realism and idealism consisting of nine variables is of course much larger than a system of three (plus one).
Adding  subsequently leads to a radical anatomy of meaning summarized by the slogan: Every sign is a request for compliance. For the sign's engineer enters into an exchange with a (potential) observer only to promote his interests (will). Given the predominance of the will, that is all (s)he can do and therefore actually does. The provision of empathy 'controls' to what extent individual behavior is social.
The ontology of subjective situationism — with the Schopenhauerean concept of the will as the ultimate, preintellectual ground — may be viewed as a superset of ontologies currently applied for conceptual information modeling. For it configures more variables. When some variables are 'bracketed,' subjective situationism simply 'behaves' like another ontology. It also means that subjective situationism provides a vantage point for analysis and evaluation. The treatise does not review specific modeling methods, but concentrates on a selection of primary sources — especially on speech acts and communicative action — that are among those which have influenced some modern schools of conceptual information modeling. Such underlying theories are shown to lack 'requisite variety' for modeling increasingly complex information systems.
Semiosis & Sign Exchange aims to contribute to the fundamental discussion on conceptual information modeling. Some of its concepts may appear unorthodox, when not outright unfamiliar. For example, subjectivism goes against the established objectivism of several modern scientific disciplines. As a corollary, the concept of shared meaning is, say, deconstructed. Even 'worse' from a strictly positivist point of view, the a priori nature of the will contradicts purely rationalist belief. However, such elements are all assembled into a theory with both increased rational explanatory power and improved support of practical information modeling. Maintaining focus, and for reasons of some restraint on the length of this treatise, the practical application of subjective situationism for conceptual information modeling has been largely kept outside the scope of the treatise. The reader is advised to consult the companion volume Metapattern: context and time in information models (Addison-Wesley, 2001).