James D. Arthur

A disciplined approach to adopting agile practices: the agile adoption framework

Many organizations aspire to adopt agile processes to take advantage of the numerous benefits that they offer to an organization. Those benefits include, but are not limited to, quicker return on investment, better software quality, and higher customer satisfaction. To date, however, there is no structured process (at least that is published in the public domain) that guides organizations in adopting agile practices. To address this situation, we present the agile adoption framework and the innovative approach we have used to implement it. The framework consists of two components: an agile measurement index, and a four-stage process, that together guide and assist the agile adoption efforts of organizations. More specifically, the Sidky Agile Measurement Index (SAMI) encompasses five agile levels that are used to identify the agile potential of projects and organizations. The four-stage process, on the other hand, helps determine (a) whether or not organizations are ready for agile adoption, and (b) guided by their potential, what set of agile practices can and should be introduced. To help substantiate the “goodness” of the Agile Adoption Framework, we presented it to various members of the agile community, and elicited responses through questionnaires. The results of that substantiation effort are encouraging, and are also presented in this paper.

Expanding our horizons in verification, validation, and accreditation research and practice

Many different types of modeling and simulation (M&S) applications, consisting of a combination of software, hardware, and humanware, are used in dozens of disciplines under diverse objectives including acquisition, analysis, education, entertainment, research, and training. Certification of sufficient accuracy of an M&S application by conducting verification, validation, and accreditation (VV&A) requires multifaceted knowledge and experience, and poses substantial technical and managerial challenges for researchers, practitioners, and managers. The challenges can only be met by using a very broad spectrum of approaches and expanding our horizons in VV&A. This paper presents 13 strategic directions to meet those challenges. The strategic directions provide guidelines for successful VV&A research and practice.

Evaluating the effectiveness of independent verification and validation

The complexity of todays software systems mandates a structured approach to development and a verification and validation process that ensure that the right product is built and that it is built right. A V&V process is critical for those high-consequence systems in which a software failure can result in injury or death or where live testing is not feasible. NASA Langley Research Center funded a study to examine the effectiveness of the Armys Software Engineering Evaluation System (SEES). The project led to a study designed to examine the benefits of using SEES as an independent V&V methodology. The study consisted of two independent-development groups. Each was given an identical set of requirements that outlined a solution to a particular problem. The authors asked both groups to design, code, and test their software. The results indicate that IV&V provides a significant value-added component to the software development process.

Achieving reusability and composability with a simulation conceptual model

Reusability and composability (R&C) are two important quality characteristics that have been very difficult to achieve in the Modelling and Simulation (M&S) discipline. Reuse provides many technical and economical benefits. Composability has been increasingly crucial for M&S of a system of systems, in which disparate systems are composed with each other. The purpose of this paper is to describe how R&C can be achieved by using a simulation conceptual model (CM) in a community of interest (COI). We address R&C in a multifaceted manner covering many M&S areas (types). M&S is commonly employed where R&C are very much needed by many COIs. We present how a CM developed for a COI can assist in R&C for the design of any type of large-scale complex M&S application in that COI. A CM becomes an asset for a COI and offers significant economic benefits through its broader applicability and more effective utilization.

Accomplishing reuse with a simulation conceptual model

Reuse has been very difficult or in some cases impossible in the modeling and simulation (M&S) discipline. This paper focuses on how reuse can be accomplished by using a conceptual model (CM) in a community of interest (COI). We address the issue of reuse in a multifaceted manner covering many areas (types) of M&S such as discrete, continuous, Monte Carlo, system dynamics, gaming-based, and agent-based. M&S is commonly employed and reuse is critically needed by many COIs such as air traffic control, automobile manufacturing, ballistic missile defense, business process reengineering, emergency response management, military training, network-centric operations and warfare, supply chain management, telecommunications, and transportation. We present how a CM developed for a COI can assist in reuse for the design of any type of large-scale complex M&S application in that COI. A CM becomes an asset for a COI and offers significant economic benefits through its effective reuse.

Determining the Applicability of Agile Practices to Mission and Life-Critical Systems

Adopting agile practices brings about many benefits and improvements to the system being developed. However, in mission and life-critical systems, adopting an inappropriate agile practice has detrimental impacts on the system in various phases of its lifecycle as well as precludes desired qualities from being actualized. This paper presents a three-stage process that provides guidance to organizations on how to identify the agile practices they can benefit from without causing any impact to the mission and life critical system being developed.

The methodology roles in the realization of a model development environment

The definition of “methodology” is followed by a very brief review of past work in modeling methodologies. The dual role of a methodology is explained: (1) conceptual guidance in the modeling task, and (2) definition of needs for environment designers. A model development environment based on the conical methodology serves for specific illustration of both roles.

A Soft-Structured Agile Framework for Larger Scale Systems Development

One of the more important issues in the development of larger scale complex systems (product development period of two or more years) is accommodating changes to requirements. Requirements gathered for larger scale systems evolve during lengthy development periods due to changes in software and business environments, new user needs and technological advancements. Agile methods, which focus on accommodating change even late in the development lifecycle, can be adopted for the development of larger scale systems. However, as currently applied, these practices are not always suitable for the development of such systems. We propose a soft-structured framework combining the principles of agile and conventional software development that addresses the issue of rapidly changing requirements for larger scale systems. The framework consists of two parts: (1) a soft-structured requirements gathering approach that reflects the agile philosophy i.e., the Agile Requirements Generation Model and (2) a tailored development process that can be applied to either small or larger scale systems.

Towards a Taxonomy of Vulnerabilities

This paper presents a taxonomy of vulnerabilities created as a part of an effort to develop a framework for deriving verification and validation strategies to assess software security. This taxonomy is grounded in a process/object model of computation that establishes a relationship between software vulnerabilities, an executing process, and computer system resources such as memory, input/output, or cryptographic resources. That relationship promotes the concept that a software application is vulnerable to exploits when it permits the violation of (a) constraints imposed by computer system resources and/or (b) assumptions made about the usage of those resources. The taxonomy identifies and classifies these constraints and assumptions. The process/object model also serves as a basis for the classification scheme the taxonomy uses. That is, the computer system resources (or objects) identified in the process/object model form the categories and refined subcategories of the taxonomy. Vulnerabilities, which are expressed in the form of constraints and assumptions, are classified within the taxonomy according to these categories and subcategories. This taxonomy of vulnerabilities is novel and distinctively different from other taxonomies found in literature

VA III: verification and validation without independence: a recipe for failure

Verification and validation (V&V) is a prominent technical area within simulation, attested to by the 12 tutorial sessions (including five advanced) included in the past ten Winter Simulation Conferences (WSCs). In recent WSCs the issue of independent V&V (IV&V) has drawn increased attention, with sessions examining the perceived lack of use and little concern for the technique evinced within the simulation community. The objectives of this paper are four-fold: to examine the current picture in software systems development; to review the rationale, role and expressed need for IV&V; to identify the benefits attendant in the insistence on the independent status of the activity; and to respond to the usual criticisms of negative impacts on cost and schedule. While the treatment is couched in the more general software systems context, we contend that simulations represent prime candidates for IV&V application.