The Technological Knowledge Strand Explanatory Papers Updated May 2010
Technological Systems
Key Ideas
Technological outcomes may be referred to as technological products and/or technological systems (see Characteristics of Technological Outcomes for an explanation of why the same outcome could be referred to as both a product and system). However, in this component, the focus is on understanding the physical nature of a technological outcome as viewed as a system, and therefore it is componentry and process understandings that are key to this component.
Technological systems are defined as a set of interconnected components designed by people to fulfil an intended function without further human design input. This means that while a technological system may include input from people to allow the system to function, this input does not alter the system design, and therefore, intended function. For example, while a person driving a car may apply the brakes (human input to activate the system), the functioning of the brake system (as a technological system) is not reliant on this person's design input.
People may be involved in making judgments around intended functions through selecting a particular setting for a manufacturing production system; however, once selected, the designed function continues as intended. The judgment, therefore, again exists as an input to the technological system. Similarly, quality control decisions around outputs can also be inputs to the technological system, providing impetus for a changing of operational parameters. Over time, system feedback may lead to a need for the system's re-design.
The knowledge base underpinning these generic concepts will vary depending on the specific nature of the technological system being explored and/or developed. For example, the understandings required to develop biotechnological systems differ significantly to those required to develop electronic control systems. However, the key concepts underpinning technological systems are those generic concepts that relate to how the inputs are transformed to outputs and what is involved in the control of this. Inputs to technological systems include such things as raw materials, information, and energy.
Outputs from technological systems include the intended outcome of the system. For example, the output of a manufacturing system for Easter eggs is the egg itself. The output of a telephone communication system is transformed and transported information – that is, a voice in another location. The output of a wind-based energy generation system is transformed and stored energy – that is, electricity. However, most technological systems also produce other outputs such as heat and waste products – including pollution. These may be known or unknown at the time of development.
Transformation processes are those processes that occur within a system, to ensure the inputs are transformed into the outputs in a controlled and intended way, without need for additional human design input. Simple technological systems are defined in this context as systems that have been designed to change inputs to outputs through a single transformation. Other systems may involve one or more subsystems. The role of subsystems is to act as a component of a larger technological system in a way that supports that system's overall function. The properties of a subsystem refer to its transformation performance and its level of connective compatibility. The role a subsystem is playing can be established by examining the way in which the inputs change to outputs during that part of the system. Where subsystems exist, effective interfaces are critical for the successful function of the system as a whole.
Control mechanisms within a system are designed to enhance the efficiency of the technological system by maximising the desired outputs and minimising the undesirable outputs. Adjustments to the transformation processes can be a part of a system's design, whereby feedback from any part of the system allows for ongoing responsiveness to input requirements and/or output success, thereby allowing the system to be self regulatory.
Self-regulatory systems are different to intelligent systems. Intelligent systems are those that have been designed to adapt to environmental inputs in ways that change the nature of the system components and/or transformation processes in known and unknown ways to produce hopefully desirable but unspecified outputs.
An exploration of generic concepts, such as redundancy and reliability within a technological system's design and performance, is important in supporting the development of understandings about a system's operational parameters. Operational parameters of systems refer to the boundaries and/or conditions within which the system has been designed to function. These concepts are important to understand when establishing the fitness for purpose of technological systems. Ethics play a significant part in the decisions around reliability and redundancy, as improvements in both these areas within a system inevitably comes with associated costs.
The concept of redundancy within a technological context refers to the inclusion of more time, information, and/or resources than would strictly be needed for the successful functioning of the technological system. Redundancy may be built into a technological system as a contingency plan to allow room for detecting or tolerating faults before the success of the system is compromised. This concept can be thought of as 'allowing a bit extra' or taking a 'belt and braces' approach to design, and can be understood at varying levels of complexity. While the inclusion of redundancy options in a system may provide additional capability, often in terms of increasing safety margins, redundancy can also result in over engineering a system by including components that provide no added functional advantage to the system. This form of redundancy is something system designers strive to eliminate as it often impacts on a system's ability to function within agreed specifications; for example, specifications around the cost of production.
An example of simple redundancy measures can be seen in the use of component parts with tolerances higher than those required to make the system fit for purpose. Within complex system design, a broad understanding of redundancy is required to ensure all variables (produced by multiple levels of interconnectedness) are included in decision making.
The concept of reliability within this context relates to the probability that a system, or sub-system, will perform a required function under stated conditions for a stated period of time. Reliability is, therefore, a part of that system's overall design and that of its constituent parts. Tolerances for reliability are determined by the specifics of each development and the nature of the output. For example, if the system is designed to result in an output that enhances human safety, reliability tolerances will be more stringent. Reliability as a concept underpins understandings associated with all three types of situations where a technological system no longer functions successfully. These three types being: malfunctioning; a gradual reduction in function caused by ongoing use; and designed failure.
The concept of a black box is important in describing technological systems. A black box can be thought of as representing a part of a technological system that is reduced to inputs, outputs, and a hidden transformation process or series of processes. There are advantages and disadvantages in adopting a black box approach when working with and understanding technological systems.
An advantage is that it can provide an opportunity for complex systems to be explored and understood in a holistic sense. It also allows for system maintenance to be undertaken without in-depth knowledge, through the replacement of isolated parts of a system with little to no disruption to the rest of the system. Ease of such replacement would be an inherent part of the system design and would need to take into account such things as the costs associated with the disposal of a part when repair of the part could have sufficed.
A significant disadvantage of black boxing is that the detail is rendered invisible, and, therefore, not available to be understood. This may pose problems in future system modification and/or development. It may also result in a loss of empowerment for the end-user, particularly should any malfunction occur or when troubleshooting or repair work is required.
Technological systems are often represented in symbolic ways to communicate their constituent parts. While there are some generic symbols associated with systems, for example, arrows to denote direction, specialised languages also exist and are central to the development and communication of technological systems. Design concepts of systems can, therefore, be represented using a variety of communication tools (for example, computer software, flow diagrams, web diagrams, 3-D models, etc.) in order to explore and understand relationships between parts of a single system and/or between different systems. Different technology communities often supplement or modify generic symbols as part of more specialised diagrams/representations to communicate system-related details. System-related details include such things as what components would be feasible, layout requirements, and how they would need to be connected.
