Redefining Functional Requirements through Human Views for MODAF: An Application of Enterprise Architectures to ensure Human Factors Integration

Abstract

Human Factors Integration (HFI) needs to be understood and practiced as an integral part of Systems Engineering (SE). It cannot be conducted in isolation. By modelling an Enterprise as a whole, MODAF (the Ministry of Defence Architectural Framework) provides an overview perspective that aids acquisition management. MODAF has the potential for fulfilling essential objectives of HFI: integrating the different HFI domains; integrating with other engineering disciplines; managing the need for HFI activities; informing trade-off analyses.

To achieve effective HFI, it is important to clarify the scope of the formal HFI design decisions areas to be influenced by suitable HFI activities. MODAF provides models to reason about acquisition decisions for future systems early, in the absence of real systems that can be observed. It supports high-level reasoning behind requirements by mapping the effects of change on other elements. It provides a common reference through a shared model, and by providing standardised representations. It is an essential tool to support capability-based acquisition.

MODAF can support HFI, as much as HFI can support MODAF. Military systems often operate in distributed environments and collaborative settings. They require the specification not only of the information systems (i.e. software and hardware), but also the social, organisational, procedural, task, and skill structures that support complex information flows and information sharing.

In order to address these concerns, a set of Human Views (HVs) is proposed, as complementary to the existing MODAF Views. HVs model the ‘soft systems’ human elements, without which future systems are likely to fail. To be able to specify all Defence Lines of Development (DLOD), they need to be specified explicitly. HVs clarify the HFI design elements of socio-technical systems. They support the change of focus from technology-focused functional requirements to capability requirements.

The HVs emphasise a model-based approach by specifying conceptual data elements for each View that can be integrated into the MODAF Meta-model. Each HV is supported by a small meta-model, showing how the HV data elements relate. An overview meta-model of all HV elements is included. Moreover, visualisation options are specified.

The HVs aim to bring together SE and HFI as two related disciplines. Whilst SE and HFI depend on each other, each is grounded in a set of approaches and philosophies not immediately compatible. By choosing a SE approach to express HFI design decision areas, HFI professionals are provided with means to communicate to Systems Engineers. On the other hand, the HV elements have the potential of changing traditional SE approaches that can be overly technology focused. Enterprise Architectures are being conceived to overcome this problem and specify requirements and solutions for all DLOD. MODAF version 1.1 has already significantly modified many of its underlying definitions. The HVs further expand on this development. The presentation discusses the nature of these differences and changes. It presents some of the HV concepts and applications.

• For further information e-mail Dr Anne Bruseberg.

(Any views expressed in this paper are those of the authors and do not necessarily represent those of the UK MoD)