EXAM4 Flashcards
What is the definition of a (web) service?
an act or performance offered by one party to another. Although the process may be tied to a physical product, the performance is essentially intangible and does not normally result in ownership of any of the factors of production
List 4 benefits of using a service-oriented approach to software engineering.
- Services can be offered by any service provider inside or outside of an organization, so organizations can create applications by integrating services from a range of providers
- Applications can delay the binding of services until they are deployed or until execution.
- Opportunistic construction of new services is possible
- Service users can pay for services according to their use rather than their provision.
What is service engineering
The process of developing services for reuse in service-oriented applications; has to be designed as a reusable abstraction that can be used in different systems
Key service engineering process stages?
Process: Service candidate identification(service requirements)> Service design(logical service interface)>Service implementation and deployment(validated and deployed service)
What is a workflow (related to service-oriented SE)
Workflows are logical sequences of activities that, together, model a coherent business
process
What are the six stages in service construction by composition?
Formulate outline workflow, discover services, select services, refine workflow, create workflow, test service
What is the difference between a technical and a sociotechnical system?
Tech : Include hardware and software but not humans or organizational processes. Off the shelf applications, control systems, etc
Socio: Include technical systems plus people who use and manage these systems and the organizations that own the systems and set policies for their use. Business systems, command and control systems
What are the four principal stages of systems engineering
Conceptual design, procurement or acquisition, development, operation
What are three influences on the reliability of a system?
Hardware reliability, software reliability, operator reliability
What five activities are part of the conceptual design process?
Concept formulation, Problem understanding, System proposal development, Feasibility study, System structure development, System vision document
What are the five main drivers for system procurement decisions?
The state of other organizational systems and whether or not they need to be replaced
The need to comply with external regulations
External competition
Business re-organization
Available budget
What are the five main factors (including costs) that influence the lifetime of a system?
Changes must be analyzed from a technical and business perspective;
Sub-systems interact so unanticipated problems can arise;
There is rarely a rationale for original design decisions;
The system structure is corrupted as changes are made to it.
Rules and policies changes can affect the lifetime
List 5 important characteristics of embedded systems that differentiate these systems from other types of computer systems
Embedded systems generally run continuously and do not terminate.
Interactions with the system’s environment are unpredictable.
There may be physical limitations that affect the design of a system.
Direct hardware interaction may be necessary.
Issues of safety and reliability may dominate the system design.
What two types of stimuli must be handled in a real-time system?
Periodic stimuli. Stimuli occur at predictable time intervals
Aperiodic stimuli. Stimuli occur at unpredictable times
What is a circular buffer and how is it used in real-time systems?
