Systems science

Systems science, also referred to as systems research, or, simply, systems, is a transdisciplinary field concerned with understanding systems—from simple to complex—in nature, society, cognition, engineering, technology and science itself. The field is diverse, spanning the formal, natural, social, and applied sciences. To systems scientists, the world can be understood as a system of systems. The field aims to develop transdisciplinary foundations that are applicable in a variety of areas, such as psychology, biology, medicine, communication, business management, technology, computer science, engineering, and social sciences. Themes commonly stressed in system science are (a) holistic view, (b) interaction between a system and its embedding environment, and (c) complex (often subtle) trajectories of dynamic behavior that sometimes are stable (and thus reinforcing), while at various 'boundary conditions' can become wildly unstable (and thus destructive). Concerns about Earth-scale

Foundations of systems and properties

Otto Preiss

Engineering of software-intensive systems is concerned with the creation and evolution of systems that shall exhibit desired properties in their execution as well as development environment. In this context, the motivation of this thesis, derived from current development practice, was twofold. Firstly, software development methods are increasingly required to extend their scope of applicability towards systems engineering. As a consequence, their modeling approaches must be able to cope with a larger diversity of systems and consequently a larger diversity of properties. But these approaches still need to provide a smooth transition to software modeling. Secondly, non-functional properties, which are largely a result of this implicit systems scope, play a major role in the way we design our software-intensive systems. The conceptual aids of current development methods, however, are still less mature in their explicit support for non-functional properties compared with their ability to support functional ones. The principal objective of this thesis is to contribute toward an improved model-based treatment of non-functional properties in development methods. Because we cannot discuss properties independently of the objects they are ascribed to, this objective amounts to a progression from modeling of software and its properties to modeling of interrelated systems and their properties. To address this aim a philosophy of properties and systems is proposed. The philosophy is expressed as a holistic conceptual model of properties and/of systems. It is complemented with some basic rules, which we call tenets. Tenets formulate how we use the philosophical knowledge. The conceptual model offers the foundations for a more generalized understanding of those fundamentally different types of systems and different types of properties that are relevant in software-intensive systems engineering. The generality of our holistic model draws the benefits from our investigations in the areas of systems science, cognitive science, and basic philosophy. The model helps to scrutinize and make sense of the large amount of data in the literature about "non-functional" issues in software engineering. The model is applicable in the derivation of methodological building blocks that can be incorporated into development methods. The building blocks include (a) a general model to discover stakeholders and properties for a given system, (b) a principled manner to trace the fundamentally different types of properties through hierarchies of systems, and (c) a proposal for the representation of systems, their properties and property traces in the UML. The concrete application of the gained knowledge to software engineering results in a proposal for a context-sensitive, customizable quality attribute model. It also results in a proposal on how to structure quality descriptions of software components. In order for such descriptions to be standardized and possibly tool-automated, this thesis proposes to utilize the Reusable Asset Specification and suggests alternatives for its XML-based representation.

EPFL2004

Stakeholder Discovery and Classification Based on Systems Science Principles

Otto Preiss, Alain Wegmann

It is the goal of our research work to elaborate on improvements to the software development methods so that quality attributes can be handled more systematically. By quality attributes we mean the large group of typically systemic properties of a software system, such as availability, security, etc., but also reusability, maintainability and many more. We define quality attributes as stakeholder-centric conditions on the behavior or structure of a system. The importance of the notion of a stakeholder cannot surprise, but the lack of a general theory on how to define and identify the relevant set of stakeholders does. Drawing from systems theory we claim that four basic, generic types of stakeholders are sufficient to be able to derive a specialized set of stakeholders for any considered system and domain of inquiry. It is only when we understand the generic concepts and principles behind quality properties of systems, that we can properly derive methods and build tools to cope with them.

2001

Foundations of systems and properties

Otto Preiss

EPFL2004

Systems Science and Sustainability Assessment

Foundations of systems and properties

Stakeholder Discovery and Classification Based on Systems Science Principles

Foundations of systems and properties

Systems Science and Sustainability Assessment

Stakeholder Discovery and Classification Based on Systems Science Principles