Object-oriented Process, Environment, and Notation (OPEN) is the premier third-generation, public domain, full lifecycle, process-focussed, methodological approach that was designed for the development of software intensive applications, particularly object-oriented and component-based developments. OPEN was developed and is maintained by the not-for-profit OPEN Consortium, an international group of over 35 methodologists, academics, CASE tool vendors and developers. OPEN was initially created by the merger of earlier methods: MOSES, SOMA, Firesmith, Synthesis and more recently enhanced by state of the art ideas from BON, Ooram, UML etc.
OPEN is defined as a process framework, known as the OPF (OPEN Process Framework). This is a process metamodel from which can be generated an organizationally-specific process (instance). Each of these process instances is created by choosing specific Activities, Tasks and Techniques (three of the major metalevel classes – see below) and specific configurations thereof. This is process construction. Process tailoring may also be needed whereby details of the Tasks and Techniques are “tweaked” for optimum fit to the problem domain.
OPEN thus provides flexibility. Derived from the metamodel-based framework, an OPEN process can be tailored to suit individual domains or projects taking into account personal skills, organizational culture and requirements peculiar to each industry domain. Consequently, while OPEN is a process framework, it can be regarded, more loosely, as a family of processes. On both counts, it is a highly flexible componentized methodological approach to building software and software intensive systems as well as offering support for business modelling. OPEN supports not only a use case driven approach but also a responsibility driven approach, a document driven approach and so on. It supports equally a translational approach versus an elaborational approach.
OPEN’s flexibility also permits it to be used on small projects and large, mission critical projects – not with the same process instance of course but with specifically engineered instances of OPEN. It can be used on rapid turnround web developments which may have short lifetimes or on business core software that must be of high and enduring quality.
OPEN provides strong support for the full lifecycle of a software application. It has an embedded project management and reuse framework; it supports business process modelling; offers guidelines on migration strategies and supports links to human relations issues. A prime concern of OPEN is software quality and the use of metrics. To that end, close links with quality frameworks including the Software Engineering Institute’s Capability Maturity Model are maintained and supported, and links to the new OOSPICE software process improvement project are strong.