Alistair Mavin

Independent Requirements Specialist

Why are requirements so hard to write? Shouldn’t it be a simple thing to do? Setting aside the issues of requirements analysis and management, even the expression of a single requirement is a two-stage process, and neither of those processes is necessarily easy. First you have to determine the need, then you have to find a clear way to express it....

The development of complex systems frequently in-valves extensive work to elicit, document and review stakeholder requirements. Stakeholder requirements are usually written in unconstrained natural language, which is inherently imprecise. During system development, problems in stakeholder requirements inevitably propagate to lower levels. This crea...

During a previous study, five simple templates were proposed to improve the quality of Natural Language requirements. That study applied the Easy Approach to Requirements Syntax (EARS) templates to the requirements for the certification of an aero engine control system contained in an airworthiness regulatory document. This paper reports on a wider...

The Easy Approach to Requirements Syntax (EARS) is an approach for authoring natural language requirements using a simple template with an underlying ruleset. EARS applies a series of keywords to denote separate clauses within a requirement. Application of the template produces natural language requirements in a small number of patterns. EARS has p...

The first easy Approach to Requirements Syntax (EARS) paper was published 10 years ago.1 (For more information, see "Introduction to the Easy Approach to Requirements Syntax.") As the original authors, we were initially unsure about publishing because we thought that EARS was too simple: almost too obvious to be of value. It turns out that it is th...

To undertake requirements engineering (RE) activities effectively and reduce project risk, you need people, processes, and technology to work together to capture the requirements and communicate clearly to all relevant stakeholders throughout the entire system development process. This paper will discuss some of the issues that arise during RE and...

A complete set of system requirements must include requirements to mitigate deviant behaviour. However, deviation analysis typically focuses on system design, not on requirements. This paper analyses requirements written in Easy Approach to Requirements Syntax (EARS) early in the system development lifecycle. This identifies deviations and mitigati...

The number of papers and articles on goals would suggest that goal-oriented requirements engineering is a well understood and mature area within the requirements engineering discipline. In particular, there is a wealth of published material on formal goal modelling approaches. However, the uptake of the goal approaches advocated by academics and re...

EARS is a technique used by Rolls-Royce and many other organizations around the world to capture requirements in natural language in a precise manner. In this paper we describe the EARS-CTRL tool for writing and analyzing EARS requirements for controllers. We provide two levels of analysis of requirements written in EARS-CTRL: firstly our editor us...

What is an ideal collaboration from a research perspective? An archetypical researcher would answer • aligns perfectly with existing research directions • brings in revenue from industry • provides the opportunity to cite blue-chip company use of research methods and tools • generates many conference papers What is an ideal collaboration from an in...

Requirements engineers aim to write correct, consistent and complete requirements. While these aspirations are admirable, many problems can conspire to hinder such aims. One common problem is the specification of safety requirements. These requirements, often covered by platitudes as " Make the system safe, " add little value. Later, as the design...

Requirements engineering (RE) often needs creativity in a form where interactions among stakeholders are particularly important: collaborative creativity. However, few studies have explicitly concentrated on understanding collaborative creativity in RE, resulting in a lack of well-founded advice for practitioners on how to support this aspect of RE...

Research is often inspired by visions of the future. These visions can take on various narrative forms, and can fall anywhere along the spectrum from utopian to dystopian. Even though we recognize the importance of such visions to help us shape research questions and inspire rich design spaces to be explored, the opportunity to discuss them is rare...

This position paper reflects on recent work that sought to make positive changes to the IEEE Requirements Engineering conference (RE), and on twenty years of requirements engineering (REng) research. We question the values that seem to underpin RE, and offer what we believe are more appropriate values. We argue that these new values would result in...

The purpose of requirements validation is to determine whether a large requirements set will lead to the achievement of system-related goals under different conditions – a task that needs automation if it is to be performed quickly and accurately. One reason for the current lack of software tools to undertake such validation is the absence of the c...

Requirements engineering (RE) often entails interdisciplinary groups of people working together to find novel and valuable solutions to a complex design problem. In such situations RE requires creativity in a form where interactions among stakeholders are particularly important: collaborative creativity. However, few studies have explicitly concent...

[Context and Motivation] The word "creativity" is used widely in business and academia, but its meaning may differ greatly depending on context. This may cause confusion in the minds of requirements engineers who have to determine which kinds of creativity are relevant to their project and which creativity tools to use. [Question/Problem] The main...

Rolls-Royce control systems are complex, safety critical systems, developed in ever-compressed timescales. Scenario techniques have been investigated, to determine if they can enhance the development process by fostering closer integration between different disciplines and by improving requirements derivation and design evaluation. A study was unde...

Rolls-Royce control systems are complex, safety critical systems, developed in ever-compressed timescales. Scenario techniques have been investigated, to determine if they can enhance the development process by fostering closer integration between different disciplines and by improving requirements derivation and design evaluation. A study was unde...

Rolls-Royce control systems are complex, safety critical and developed in ever-compressed timescales. Scenario techniques are utilised during systems design, safety analysis and systems verification. Scenarios can be used to improve requirements quality and to ensure greater confidence in requirements coverage for both normal and exception behaviou...

Ian Alexander has been trying to persuade me to contribute to RQ for many years. All he needed to do was misquote me in these pages, and I’d surely have written an article long ago. Luckily for him, the review of the recent RESG Soapbox event (reported in RQ45) did not accurately report my contribution to the debate. I have therefore taken this opp...

The article consists of a Powerpoint presentation on scenario modelling. A scenario is a specific sequence of actions that illustrates behaviour. A scenario framework helps us to express a scenario. Use cases relate a system's requirements to its environment. Requirements engineering process must thoroughly explore system boundaries prior to modeli...

Scenarios are effective for discovering requirements, but we still do not understand what types of scenario and which walkthrough techniques are most effective. We report the application of one scenario approach - CREWS-SAVRE - to discover requirements for naval and air traffic management systems with BAE Systems and Eurocontrol respectively. Resul...

Organisations are seeking to improve the way they undertake engineering activities. There are numerous ways of doing this, one of which is to undertake an on-going process, or capability, enhancement activity. Praxis Critical Systems Limited provides support for such activity based primarily around the REVEAL® requirements engineering method. By pr...