Chapter 1 Flashcards
From the Greek word “systema” means “organized whole”
System
A regularly interacting or interdependent group of items forming a unified whole
System
A combination of interacting elements organized to achieve one or more stated purposes
Engineered System
It is a specialization of system which fulfills the basic properties of all systems, but which is explicitly man-made, contains technology, exists for a purpose and is engineered through a series of managed life cycle activities to make it better able to achieve that purpose
Engineered System
Is an interdisciplinary, collaborative approach to the engineering of systems which aims to capture stakeholder needs and objectives and to transform these into a description of a holistic, life-cycle balanced system solution which both satisfies the minimum requirements and optimizes overall project and system effectiveness according to the values of the stakeholders.
Systems Engineering
Incorporated both technical and management processes
Systems Engineering
They must analyze, specify, design, and verify the system to ensure that its functional, interface, performance, physical, and other quality characteristics, and cost are balanced to meet the needs of the system stakeholders
Systems Engineer
They helps ensure the elements of the system fit together to accomplish the objectives of the whole, and ultimately satisfy the needs of the customers and other stakeholders who will acquire and use the system
Systems Engineer
They support a set of life cycle processes beginning early in conceptual design and continuing throughout the lifecycle of the system through its manufacture, deployment, use and disposal.
Systems Engineer
The degree to which a system’s design or code is difficult to understand because of numerous components or relationships among components
Complexity
The principle that whole entities exhibit properties which are meaningful only when attributed to the whole, not to its parts
Emergence
Building blocks of a systems and contains hardware, software, personnel, facilities, policies, documents, and databases
Elements
made up of combinations of elements
System
can be divided into a hierarchy of sets of elements, that include subsystem, components, subcomponents, and parts
System
Elements of a System
- Components
- Attributes
- Relationships
is a set of interrelated components functioning together toward some common objectives or purposes
System
operating parts of the systems contains input, process, and output
Components
properties (characteristic, configuration, qualities, powers, constraints, and state) of the components and of the system as a whole
Attributes
between pairs of linked components are the result of engineering the attributes of both components so that the pair operates together effectively in contributing to the system’s purpose
Relationship
Systems Components
- Structural Components
- Operating Components
- Flow Components
Always start using ______or _______
Data
Information
Advantages of Concurrent Engineering
- This model is applicable to all types of software development processes
- It is easy to understand and use
- It gives immediate feedback from testing
- Provides an accurate feature of the current state of a project
Advantage of Waterfall Process Model
- This model is simple and easy to understand and use
- It is easy to manage due to its phase has specific deliverables and review process
- Waterfall model works well for smaller projects where requirements are clearly define
and very well understood
Disadvantage of Waterfall Process Model
- No working software is produced until late during the life cycle
- Poor model for long and ongoing projects
- High amounts of risks and uncertainty
- It’s not a good model for complex and object oriented projects
collects the information, help of SRS, CRS, BRS software, customer, business requirements specifications
Requirements Analysis
Feasibility Study, high level people analyze whether the project is doable or not.
Considers economic, operation, technical, schedule
Specification
- architecture of the project. Uses HLD (flowchart, decision tree), LLD
(components), high and low level design Implementation - coding, uses program
language such java, phyton
Design
function, according to the requirements of customers or clients Installation
- if the system is bug free or virus free
Test
error correction, enhancement of capabilities, optimization
Maintenance
Waterfall Process Model
- Requirements Analysis
- Specification
- Design
- Test
- Maintenance
Advantages of Spiral Model
- It provides continuous and repeated development which helps in risk management
- It provides the past development and the futures are added in a systematic manner
- Clients get the opportunity to see the software or products after every cycle
- It is the most preferable model for large and complex projects or software
Disadvantages of Spiral Model
- Spiral models are expensive due to the high level of expertise required for risk analysis
- The spiral model is not suited for small projects
- The overall success of the project depends on the risk analysis phase
Advantages of VEE Model
- It is simple and easy to understand and execute
- Provide structured way of doing things
- Works well with the small projects
- Emphasize planning for verification and validation of the product in early stage of the development
Disadvantages of VEE Model
- Not change friendly
- Poor resources allocations
- Not suitable for complex and object oriented projects
- Need crystal clear requirements
System relationships
- first order relationship
- second-order relationships
- redundancy
Association of two systems that benefit each other
first-order relationship
An example is symbiosis
first-order relationship
called synergistic, are those that are complementary and add to system performance
second-order relationship
exists when duplicate components are present for the purpose of assuring continuation of the system function in case of component failure.
redundancy
static parts
Structural Components
a lower system, if two hierarchical levels are involved in a given system
subsystem
are the parts that perform the processing
Operating Components
four system limits, boundaries or scope
- environment
- inputs
- outputs
- throughput
everything that remains outside the boundary of a system
environment
materials, energy, information often pass through the boundaries
input
material, energy, information that pass from the system to the environment
output
enters the system in one form and leaves the system in another
throughput
are the material, energy, or information being altered
Flow Components
at whatever level in the hierarchy, consists of all components, attributes, and relationships needed to accomplish one r more objectives.
total system
purposeful action performed by a system
FUNCTION
limits an operation of a system and define the boundary within which it is intended to operate
constraints
Classification of system
- Natural system
- human-made system
- human modified system
- conceptual system
- physical system
- static system
- dynamic system
- closed system
- open system
Include those that came into being through natural processes
Natural systems
Include those that came into being through natural processes
Natural systems
Are those in which human beings have intervened through components attributes and relationships
Human made system
Is a natural system into which a human made system has been integrated as a subsystem
Human modified system
Are organizations of ideas
Conceptual system
Are those that manifest themselves in physical form those made up of real components occupying space
Physical system
Those that have structure but without activity as viewed in a relatively short period of time
Static systems
Is one whose states do not change because it has a structural components but no operating or flow components as exemplified by a bridge
Static system
Exhibits behaviors because it combines structural components with operating and or flow components
Dynamic system
Is one that is relatively self contained and does not significantly interact with its environment
Closed systems
Usually exhibit the characteristic of equilibrium resulting from internal rigidity that maintains the system in spite of influences from the environment
Closed system
Allows information energy and platter to across its boundaries. It interacts with their environment example being plants ecological systems and business organizations
Open system
They exhibit the characteristics of steady state wherein in a dynamic interaction of system elements adjust to changes in the environment
Open system
A system that are self regulatory and often self adaptive
Open system
The product life cycle
- Acquisition phase
- utilization phase
- Design phase
- startup phase
- operation phase
- retirement phase
It may involve both the customer or procuring agency and the producer or contractor
Acquisition phase
It may include a combination of contractor and customers (or ultimate user) activities
Utilization phase
Is a systematic approach to creating a system design to simultaneously considers all phases of all the life cycle from conception through disposal to include consideration of production distribution maintenance phase out and so on
Concurrent engineering
____ should not only transform a need into a system configuration but should also ensure the designs compatibility with related physical and functional requirements
Design
Introduced by Royce in 1970 initially for software development
Waterfall process model
It was introduced by boehm 1986 which is adapted from waterfall model
Spiral process model
It is a risk driven approach for the development of products or system
Spiral process model
It is a model introduced by Forsberg and Mooz
VEE process model
This model starts with user needs on the upper left and ends with a user validated system on the upper right
VEE process model
Four stages of spiral processing model
Planning
risk analysis
engineering and execution
evaluation
VEE PROCESS MODEL
- Define System Requirements
- Allocate System Functiins to Subsystems
- Detail Design of Components
- Verify Components
- Verification of Subsystems
- Full System Operation and Verification
left side - Decomposition and Definition Sequence
right side - Integration and Verification Sequence
top side - Testing
