Ch4 Technical Processes Flashcards
Why are technical processes important?
Because they enable system engineers to coordinate the interactions between engineering specialists, other engineering disciplines, system stakeholders and operators, and manufacturing. They also address conformance with the expectations and legislated requirements of society.
Without the technical processes, the risk of project failure would be unacceptably high.
What’s the definition of needs?
For a system, needs are often capabilities or things that are lacking but wanted or desired by one or more stakeholders.
What’s the definition of requirements?
Requirements are formal structured statements that can be verified and validated.
How many technical processes are there and which ones are they?
14:
Business or mission analysis,
Stakeholder needs and requirements definition,
System requirements definition,
Architecture definition,
Design definition,
System analysis,
Implementation,
Integration,
Verification,
Transition,
Validation,
Operation,
Maintenance,
Disposal.
What is the purpose of the Business or mission analysis?
Define the problem domain;
identify major stakeholders;
identify environmental conditions and constraints that bound the solution domain;
develop preliminary life cycle concepts for acquisition, operations, deployment, support, and retirement;
develop business requirements and validation criteria.
What is the “concept of operations”, or ConOps?
The ConOps addresses the leadership’s intended way of operating the organization. It describes the organization’s assumptions or intent in regard to an overall operation or series of operations of the business with using the system to be developed, existing systems, and possible future systems. The ConOps document serves as a basis for the organization to direct the overall characteristics of the future business and systems.
What is the “operational concept”, or OpsCon?
The OpsCon describes what the system will do and why. It is user-oriented and describes the system characteristics of the to-be-delivered system from the user’s viewpoint. It is used to communicate overall quantitative and qualitative system characteristics to the acquirer, user, supplier and other organizational elements.
What are the main differences between the ConOps and OpsCon?
Both are prepared by the organization that has the business need for the SOI. However, the ConOps is prepared by/for the leadership at the enterprise level and is written from a business/strategy perspective, while the OpsCon is prepared at the business level and is written from an operational perspective. Furthermore, the OpsCon may be iteratively refined as a result of feedback during the system requirements and architecture definition processes.
What is a stakeholder?
Any entity (individual or organization) with a legitimate interest in the system.
What is the purpose of the Stakeholder Needs and Requirements Definition process?
Identify the stakeholders;
Elicit the stakeholder needs;
Analyze these needs and operational scenarios;
Transform stakeholder needs into requirements.
Why are stakeholder requirements important?
Because they are the primary reference against which the operational capability is validated.
Which practical artifacts are dependent on a proper Stakeholder Needs and Requirement Definition process?
OpsCon;
StRS;
SOW (statement of work);
RFP (request for proposal);
acquisition concept;
deployment concept;
support concept;
retirement concept.
What is the purpose of the System Requirements Definition process?
To generate a set of technical requirements from the supplier’s perspective; such set shall be complete but minimum, since each requirement carries a cost. The requirements shall specify the system characteristics, attributes, functions, and performance that will meet the stakeholder requirements.
Which are the important characteristics and attributes of good requirements?
Necessary;
Implementation independent;
Unambiguous;
Complete;
Singular;
Achievable;
Verifiable;
Conforming.
What is the purpose of the Architecture Definition process?
To generate system architecture alternatives, to select one or more alternative(s) that frame stakeholder concerns and meet system requirements, and to express this in a set of consistent views.
What is the difference between architecture and design activities?
System architecture is more abstract, conceptualization oriented, global. focused to achieve the mission and OpsCon of the system, and focused on high-level structure in systems and system elements.
System design is more technology oriented through physical, structural, environmental, and operational properties forcing decisions for implementation by focusing on compatibility with technologies and other design elements and feasibility of construction and integration.
What is emergence?
The principle that whole entities exhibit properties, which are meaningful only when attributed to the whole, not to its parts. Emergent properties can be desirable and undesirable. The latter shall be avoided, with help of analysis of interaction between entities.
What are coupling matrices (or N2 matrices?).
A basic method to define the aggregates and the order of integration. Used during architecture definition, with the goal of keeping the interfaces as simple as possible.
What is the purpose of the Design Definition process?
To provide sufficient detailed data and information about the system ad its elements to enable the implementation consistent with architectural entities as defined in models and views of the system architecture.
What is holistic design?
An approach to design that considers the system being designed as an interconnected whole, which is also part of something larger. Holistic design is about more than merely trying to meet the system requirements.
What is the purpose of the System Analysis process?
To provide a rigorous basis of data and information for technical understanding to aid decision-making across the life cycle.
What is the purpose of the Implementation process?
To realize a specified system element.
What is the purpose of the Integration process?
To synthesize a set of system elements into a realized system (product or service) that satisfies system requirements, architecture , and design.
Describe the global integration technique.
A.k.a. “big bang” integration, all system elements are assembled in one step.
+ simple;
+ does not require simulation;
- difficult to detect and locate faults;
- interface faults detected late.
Describe the integration “with the stream” technique.
The system elements are assembled as they become available.
+ quick start of integration;
- complex to implement due to simulation needs;
- impossible to control functional chains end-to-end;
- global tests postponed very late.
Describe the incremental integration technique.
A few system elements are added to an already integrated increment of system elements in a predefined order.
+ allows fast localization of faults;
- requires simulators for absent system elements;
- requires many test cases.
Describe the subset integration technique.
System elements are assembled by subsets, and then subsets are assembled together.
+ saves time due to parallel integration of subsets;
+ enables delivery of partial product;
+ requires less means and fewer test cases.
Describe the top-down integration technique.
System elements or aggregates are integrated in their activation or utilization order.
+ availability of a skeleton of the system possible;
+ early detection of architectural faults;
+ definition of test cases close to reality;
+ possible reuse of data set;
- necessity to create many stubs/caps;
- difficult to define test cases of leaf system elements.
Describe the bottom-up integration technique.
System elements or aggregates are integrated in the opposite order of their activation or utilization.
+ easy definition of test cases;
+ early detection of faults (in leaf elements);
+ reduced number of simulators used;
- test cases to be redefined for each step;
- drivers are difficult to define and realize;
- lower-level elements are overtested;
- no quick detection of architectural faults.
Describe the criterion-driven integration technique.
The most critical system elements (w.r.t. a chosen criterion) are firstly integrated.
+ allows early testing;
+ allows for early verification of architecture and design choices;
- difficult to define test cases;
- difficult to define data sets.
What is the purpose of the Verification process?
To provide objective evidence that a system or system element fulfils its specified requirements and characteristics.
What is the difference between verification and validation?
Verification is intended to ensure that the “product is built right”, while validation is intended to ensure that the “right product is built”.
List the basic verification techniques.
1) Inspection;
2) Analysis;
3) Demonstration;
4) Test;
5) Analogy or similarity;
6) Simulation;
7) Sampling.
What is the purpose of the Transition process?
To establish a capability for a system to provide services specified by stakeholder requirements in the operational environment. Ultimately, it enables the transfer of custody of the system and responsibility for system support from one organizational entity to another.
