Services

Samares Engineering has strong experience in requirement identification and definition. Those requirements can be detailed expectations coming from stakeholders concerning a new or changed system or a tool; they can also be system or software requirements specification (write what system or tool will do to meet stakeholder expectations). Quality of requirements can be guided by use of boiler plates and checked by application of rules/queries. Some tools are specialized in that guidance and help defining good quality textual requirements.

When a system is complex and/or safety critical and needs many efforts to ensure consistency between requirements, we suggest combining technics presented above with modelling approach to transform needs and expectations into requirements and to derive system requirements into subsystem, software and hardware requirements.

Modelling especially helps in reaching mature requirements early in the cycle through the following activities:

  • identification/capture of requirements through use of different view points about system context
  • consistent formalizing of requirements: local consistency by construction through the use of diagrams  and global consistency by the use of a systematic approach to links the different model elements: helps in detecting ambiguities, errors or missing elements in expectations or in system definition in the first iterations
  • verification and validation of requirements early in the development cycle through analysis, review and simulation with stakeholders in the loop

Concerning requirement management tools, we have good experience on most of those used by large industrial companies today: see Requirement Tool Selection tab to get a good idea.

Concerning modeling tools useful to formalize requirements,  see Modeling tools

We help in identifying key activities that concern requirement engineering from elicitation of stakeholder requirements (if needed) to the generation of specification document with traceability links and including version control management, configuration management in a context of collaborative work potentially with a team distributed on several locations.

We help checking conformance of those engineering activities with the domain specific engineering standards (ARP4754A, DO 178B/C, ECSS-E-ST {10, 40,80},  CENELEC EN{59026, 28, 29}… and we can highlight deviations if requested.

In case of a model-based engineering process we highlight challenges concerning traceability with model elements. As an example, here are some key questions that need to be addressed to use models efficiently and support impact analysis through fine-grained requirement traceability:

  • Where should we store the links between requirements and model elements? in the RM tool? in the model? else?
  • How do we track that a traceability link is suspect?  it can become suspect because the requirement changed but also because the model element(s) changed… and sometime the model changed but not the model element that is the traceability link target (for instance a UML package may have its content change even itself it did not change…)
  • Can we trace requirements to diagrams ?
  • How to maintain traceability links when requirements and models evolve concurrently?
  • …
We start from ISO/IEC TR 24766:2009 standard criteria and complete them with customer specific context concerning requirement engineering process and tools to integrate with.

As an example for software engineering, as upstream requirements come from system team and are generally quite well described, there is no need to request strong requirement elicitation capabilities.

As another example, if system or software engineer needs to trace requirement links with modeling tools that run on their computer, key criteria shall include ability to connect to the computer tool, what is not always supported by full web-based solutions.

Here is below a list of RM tools that we have evaluated for customers recently:

    • Polarion (Siemens)
    • Integrity Lifecycle Manager (PTC)
    • Aras Innovator (Aras)
    • JAMA (Jama Software)
    • DOORS NG (IBM)
    • Reqtify (Dassault Systems)
    • Eclipse RMF (Eclipse community)

Main idea is to use models in order to formalize requirements and derive them at different levels of refinement  so that we can establish traceability through modelling approach.

Samares Engineering has coordinated a project at AFIS, (INCOSE French chapter) on requirements engineering within modeling context. The contribution of all participants let to a white paper available here: Requirements and Architecture within Modelling context.

Note: This white paper is also available from INCOSE Store: here.

Le schéma ci-dessous présente les différents types de modèles préconisés par Samares Engineering pour transformer les exigences entre les différents niveaux d’ingénierie.

utilisation des modèles pour transformer les exigences entre les niveaux

Pour plus d’information, renez-vous sur la partie “IDM” ici.

Example of mission

Customer goals:

  • Choose a requirement management tool able to:
    • Conform to the customer engineering process
    • Integrate with customer tooling environment
    • Support navigation between artifacts along traceability links, especially between requirements and design model elements
  • Get a formal tool selection process so that choice can be clearly understood by staff and other departments:
    • Formal set of criteria, clearly defined so that we can evaluate them with a score from 1 to 5
    • Rationale for high level criteria used to initiate a first list of 12 tools
    • Rationale for each criterion and for weights associated to criteria
    • Mark for evaluation of each criteria for each tool and comments to explain mark if needed
Steps/activities:

  1. Formalize engineering process to detail all required activities concerning requirement management and traceability (Import upstream requirements, derive them into current requirements, define architecture and trace it to requirements…, analyse changes in upstream requirements…)
  2. List all tools connected to requirement engineering( version control system, modeling tools used to formalize, illustrate or simulate requirements, documentation generation/management…)
  3. Define key criteria for tool selection taking into account support of Engineering process activities, integration with customer tool environment and standard criteria about requirement management tool (ISO/IEC TR 24766:2009)
  4. Perform evaluation of Requirement Engineering tools according to a set of criteria