System Entity Concepts

1-2

System Entity Concepts

Define what a system is Identify attributes, properties, and

characteristics common to most systems

Address organizational systems roles and stakeholders

Identify key factors that impact user acceptability of a system

1-3

Definition of System

The term “system” originates from the Greek term syst′ema, which means to “place together.”

The system can be defined as: An integrated set of interoperable elements, each

with explicitly specified and bounded capabilities, working synergistically to perform value-added processing to enable a User to satisfy mission-oriented operational needs in a prescribed operating environment with a specified outcome and probability of success.

1-4

Elements of System Definition

• “an integrated set” means that a system by definition is composed of hierarchical levels of physical elements, entities, or components.

• “interoperable elements” means that elements within the system’s structure must be compatible with each other in form, fit, and function.

1-5

Elements of System Definition

• “explicitly specified and bounded capabilities” means that every element should work to accomplish some higher level goal or purposeful mission.

•“working in synergistically” means that the purpose of integrating the set of elements is to leverage the capabilities of individual element capabilities to accomplish a higher level capability that cannot be achieved as stand-alone elements.

•“value-added processing” means that factors such as operational cost, utility, suitability, availability, and efficiency demand that each system operation and task add value to its inputs availability, and produce outputs that contribute to achievement of the overall system mission outcome and performance objectives.

1-61-6

Elements of System Definition

•“enable a user to predictably satisfy mission-oriented operational needs” means that every system has a purpose (i.e., a reason for existence) and a value to the user(s). Its value may be a return on investment (ROI) relative to satisfying operational needs or to satisfy system missions and objectives.

•“in a prescribed operating environment” means that for economic, outcome, and survival reasons, every system must have a prescribed—that is, bounded—operating environment.

1-71-7

Elements of System Definition

• “with a specified outcome” means that system stakeholders (Users, shareholders, owners, etc.) expect systems to produce results. The observed behavior, products, by products, or services, for example, must be outcome-oriented, quantifiable, measurable, and verifiable.

• “probability of success” means that accomplishment of a specific outcome involves a degree of uncertainty or risk. Thus, the degree of success is determined by various performance factors such as reliability, dependability, availability, maintainability, sustainability, lethality, and survivability.

System Contexts (1of 2)

Product ContextA product, as an ENABLING element of a larger system, is typically a physical device or entity that has a specific capability (form, fit, and function) with a specified level of performance.Contextually, a product may actually be a vendor’s “system” that is integrated into a User’s higher-level

system. Effectively, you create a system of systems (SoS).EXAMPLE: A jet aircraft, as a system and procurable vendor

product, is integrated into an airline’s system and may possess the capability, when programmed and activated by the pilot under certain conditions, to fly.

1-8

System Contexts (2 of 2)

Tool ContextA tool is a supporting product that enables a user or system to leverage its own capabilities and performance to more effectively or efficiently achieve mission objectives that exceed the individual

capabilities of the User or system.

EXAMPLE A statistical software application, as a support tool, enables a statistician to efficiently analyze large amounts of data and variances in a short period of time.

1-9

System Entity

As a construct, this symbolism is acceptable; however, the words need to more explicitly identify WHAT the system performs.

1-10

System Entity--Elaborated

The attributes of the construct serve as a key checklist to ensure that all contributory factors are duly considered when specifying, designing, and developing a system.

1-11

Categories of PerformanceWhen you investigate systems, you soon discover two basic categories of performance: • Objective Performance produces measurable physical evidence of system effectiveness based on pre-defined criteria. For example, the temperature of the water is 108°F.• Subjective Performance indicated by a subjective quality that varies by individual sensory values, interpretations, or perspectives. For example, is the water “warm or hot”?

1-12

SYSTEM CHARACTERISTICS

When we characterize systems, especially for analysis, there are four basic types of characteristics we consider:1) General characteristics2) Operating or behavioral characteristics3) Physical characteristics4) System aesthetics

1-13

General CharacteristicsThe high-level features of a system are its general characteristics as in marketing brochures to capture a customer’s interest. General characteristics often have some commonality across multiple instances or models of a system. EXAMPLE:• Enterprise or Organization General Characteristics 200 employees; staff with 20 PhD, 50 Master, and 30 BS degrees; annual sales of $500 M per annum.• Network General Characteristics Client-serverarchitecture, PC and Unix platforms, firewall security, remote dial-

up access, Ethernet backbone, network file structure (NFS).

1-14

Operating or Behavioral Characteristics

At a level of detail below the general characteristics, systems have operating characteristics that describe system features related to usability, survivability, and performance for a prescribed operating environment. EXAMPLES• Automobile Operating Characteristics Manoeuvrability,

turn radius of 18 ft, 0 to 60 mph in 6 seconds, etc.• Aircraft Operating Characteristics All-weather

application, speed, etc.• Network Operating Characteristics Authorization, access

time, latency, etc.

1-15

Physical CharacteristicsEvery system is described by physical characteristics that relate to non-functional attributes such as size, weight, color, capacity, and interface attributes. EXAMPLES:• Automobile Physical Characteristics 2000 lbs, curb weight 14.0 cu ft of cargo volume, 43.1 of inches (max) of front leg room, 17.1 gals fuel capacity, 240 horsepower engine at 6250 rpm, turbo, available in10 colors.• Enterprise or Organization Physical Characteristics 5000 sq ft of office space, 15 networked computers, 100,000 sq ft warehouse.• Network Physical Characteristics 1.0 Mb Ethernet backbone, topography, routers, gateways.

1-16

System Aesthetic CharacteristicsGeneral, operating, and physical characteristics are objective performance parameters. What about subjective characteristics? System aesthetic characteristics : they relate to the “look and feel” of a system. Includes psychological, sociological, and cultural perspectives that relate to appealing to the User’s, Acquirer’s, or System Owner’s preferences.

Thus, some buyers make independent decisions, while others are influenced by external systems (i.e., other buyers) in matters relating to community or corporate status, image, and the like.

1-17

UNDERSTANDING THE ROLE OF SYSTEM STAKEHOLDERS

Human-made systems, from conception through disposal, require human support, both directly and indirectly.

Humans with vested interests in a system, product, or service expect to contribute to the conceptualization, funding, procurement, design, development, and retirement of every system. These people as stakeholders. Depending on the size andcomplexity of the system, including risks and importance to the User, stakeholder roles may be performed by an individual, an organization, or some higher level enterprise such as a corporation, government, or country.

1-18

System AcceptabilityThe degree of success of any human-made system and its

mission(s) ultimately depends on:1. Whether the marketplace is ready for introduction of the

system—an operational need driven “window of opportunity.”

2. The User’s perception of the system’s operational utility, suitability, and availability.

3. The system’s ability to accomplish the User’s mission—system effectiveness.

4. The return on investment (ROI) for the resources expended to operate and maintain the system—cost effectiveness.

1-19

System AcceptabilitySystem acceptability is viewed as customer satisfaction . For Engineers often measured by customer satisfaction surveys AFTER a system has been delivered A system or product may be improved if:1. The User awards another contract to assuming the

deficiencies are not covered by the contract.2. Longer term profit projections make internal investment

worthwhile. You should understand the User’s operational needs prior to the system development.

Please see:1. HOW the User intends to use the system or product.2. WHAT measures of success are to be applied?3. The consequences and ramifications of User failure or

degrees of success.

1-20

Key Challenges in Developing Systems Acceptable to Their Users

The level of acceptance of a system is measured by a seriesof questions that are answered by analysis before a system is developed and by User feedback and actual results after the system is implemented in the field. The questions include:1. Is the timing RIGHT for the introduction of a new system? Is the marketplace “mentally and emotionally ready” ready for this system, product, or service as driven by operational needs?2. Is system feasibility sufficient to warrant User/System Developer investments that may result in a return on

investment (ROI) at a later date?

1-21

Key Challenges in Developing Systems Acceptable to Their Users

3. Does the proposed system have OPERATIONALLY UTILITY to the User relative to their organizational missions and objectives?

4. Is the proposed system OPERATIONALLY SUITABLE for all stakeholders relative to its intended application?

5. Is the proposed system OPERATIONALLY AVAILABLE when tasked to perform missions?

6. Is the system OPERATIONALLY EFFECTIVE, in terms of cost and technical performance, for its intended mission applications and objectives?

1-22

System Timing to the Marketplace

If the marketplace is not mentally or skillfully ready for the device or can afford it, your efforts and investments may be futile—timing is critical to User acceptance!

User may WANT and NEED a system yet lack sufficient funding. Or funding is “on hold” due to a lack of consensus on system’s requirements.

Organizations develop a series of decision-making “gates” that qualify the maturity of a business opportunity and incrementally increase the level of commitment, such as funding. Therefore, organizations must do their homework and work proactively with the Users to ensure that system timing is right.

1-23

System Feasibility and Affordability

If a determination is made that the timing for a system is RIGHT, the next challenge comes in determining if the system, as currently specified, can be feasibly developed and produced with existing technologies within the budget at acceptable risk for the User or Acquirer.

System feasibility ultimately focuses on four key questions:1. WHAT does the User WANT?2. WHAT does the User NEED?3. WHAT can the User AFFORD?4. WHAT is the User WILLING to PAY?An SE team is expected to conceptualize, mature,and propose technical solutions to satisfy these system feasibility questions

1-24