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components and the relationships between them.
Another essential element of the definition involves the subjective aspect: a system is not an objective “thing” out there that exists on its own but it is something attributed to a set of interrelated components by an observer.
3.1.2 The Systems View and Systems Thinking
The definition of a system is, however, somewhat of an academic exercise. The real essence of systems theory is being able to look at the world from a different perspective. The systems view involves adopting the reference framework and the terminology of systems theory, trying to apply various analogies with other systems and checking which of the systems laws and theories hold for the system of interest. Systems thinking is just a whole new way of thinking about the world in which you live. Being able to adopt this approach is quite an eye-opener for many, a pleasant and novel experience in fact, and much more important than
merely being able to explain all the various concepts that will be introduced in this chapter.
Why is this systems view so important? Can we not just learn about the technology of
information systems and dispense with more philosophical matters? The problem with the
purely technical approach is that it often fails to take into account the inter-relation of problems and proposed solutions, which is incorporated in the systems view. The study of information systems is about solving an organisation’s problems with respect to its
information needs. Installing a computer is often a quick fix but may turn out to be a very sub-optimal solution, not taking into account many of the human and organisational factors.
Some authors go even further and claim that most of today’s complex problems, such as
crime, drugs, poverty, war, suicides, breakdown of family structures, unbridled materialism, global warming and more, are a result of the short term and technicist vision of society’s decision makers who fail to adopt a holistic systems view when addressing problems.
3.2 Elements of a System
3.2.1 Environment and Boundary
As soon as we identify a system, we define a boundary: what is inside the boundary belongs to the system, everything outside the boundary is not part of the system. However, most
systems do not exist in isolation. Systems, or their components, inter-act with the world outside their boundary. The part of the outside world with which the system interacts is called the system’s environment. What about the boundary itself: do you think that it belongs to the system itself, or is it part of the environment?
3.2.2 Inputs, Transformation Process and Outputs
The interactions of a system with its environment can take the form of inputs or outputs.
Inputs take the form of material objects, energy and/or information flowing from the environment into the system. Outputs are released or sent from the system back into its environment. This output can either be useful (to some outside system) or waste. Within the system, the inputs usually undergo some kind of transformation process so that the outputs are different from the inputs. Often, inputs and outputs undergo further specific
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transformations at the system boundary; the system components responsible for these transformations are called the interfaces.
SYSTEM ENVIRONMENT
TRANSFORMATION
INPUTS
OUTPUTS
PROCESS
SYSTEM BOUNDARY
Figure 3-1: The basic elements of a system
Some systems perform very simple energy or matter transformations. Other, more complex
systems, such as our human mind, perform quite intricate and sometimes even
incomprehensible transformation processes (as evidenced by some student examination
answers!) A motor car, for instance, turns petrol and oxygen into motion, heat and a variety of waste gases (exhaust fumes). It also takes its occupants from one physical location to a hopefully different location.
Information systemsError! Bookmark not defined. accept data as input, via an interface such as a computer keyboard or barcode scanner. Transformations may be trivial (counting or
adding a set of numbers, copying a set of data), slightly more complex (e.g. drawing a map from co-ordinate data) or extremely complex (making a medical diagnosis based on
symptoms and signs, deciding whether to launch a new product range, translating a poem).
The information outputs of the system will finally be presented to end users, via an interface such as a computer screen or a printer.
3.2.3 Components and Subsystems
A system consists of various components which, taken together, make up the system. The interaction between the system components is responsible for processing the inputs into
outputs. Although components can also interact directly with elements from the environment i.e. across the system boundary, most of their interactions will be with other components within the same system.
Often, components themselves can be viewed as smaller systems on their own: they are subsystems of the system under consideration. The motor car mentioned above, for instance, has an electrical sub-system and an air-conditioning sub-system.
In the case of an information system, the basic components that interact are
• the hardware or physical equipment used to process and store data
• the software and procedures used to transform and extract information
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• the data that represents the activities of the business
• the network that permits the sharing of resources between computers
• the people who develop, maintain and use the system.
Each of these components will be discussed in more detail in later sections of this book. At the same time, don’t lose sight of the fact that the information system in turn is merely one component of the organisation, and must interact with other departments and business
activities.
To understand the workings of a system, it is often useful not to take into account all the details of each of the subsystems. The level of detail with which you study a given system is called the granularity. If you want only to drive a car, you may be satisfied with a fairly coarse granularity i.e. you need to know about such things like the ignition and petrol tank but not about the condenser or the differential. However, if you are a car fanatic or repair mechanic (or if the car does not want to start), you need a much more detailed understanding of the subsystems within the car i.e. you need to study the system at a much finer granularity.
The coarsest possible description of a system is called the black box view of the system: you just describe the inputs and outputs but make no attempt at understanding what actually goes on inside the system. When first analysing or discussing a system, it often makes sense to view its subsystems as black boxes. The telephone communication system is, for most of us, very much like a black box: we dial a number and, if all is well, we hear a familiar voice in our handset. Luckily, we do not need to know how the various telephonic exchanges managed to establish our connection or how our voice signal got transmitted. Our scientific pocket calculator is another example: when we want to calculate the cosine of a certain angle, we enter a number, press on the cosine function and it displays a result without us being aware of how in fact it arrived at this result. If a black box hides all internal system details, what do you think is meant by a white box? A grey box?
Trivial fact: The biggest machine in the world is the telephone system. The vast network of cables and satellites links together over a billion different telephones, fax machines and modems that connect a third of our world.
3.2.4 Objectives, Control and Feedback Loops
Systems have a function, goal or purpose. This goal can be internalised e.g. the desired room temperature for a central heating thermostat device or the profit motive in a commercial business enterprise. This purpose can also be imposed from the outside e.g. when we use a motor car to drive from our home to the shop. In order for the system to achieve its goal(s), it needs to be able to modify its behaviour. Control is the mechanism whereby special control signals or, when coming from outside the system, control inputs, modify the processes and activities which occur within the system.
The controller is the component or (sub-)system which exercises the control and can be part of or outside the system under consideration. The controller observes the behaviour of the system, typically by looking at certain system outputs and compares them to the desired state Discovering Information Systems
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or objective. In the case of a deviation, the controller would adjust certain (input) controls to modify the system’s processes. This ‘round trip’ of using output signals and using them to modify input signals is called a feedback loop, and the whole process is one of feedback control. There is always a slight delay before the output can be “interpreted”, the consequent control changes are effected and the system behaviour is adjusted. This delay is called the (time) lag. Lags can vary from the milliseconds it takes an ABS car braking system to release the brakes of a locked wheel to the many years it may take to vote an unpopular government out of office in a country’s democratic political governance system. In the case of a business, output from the MIS will be used to provide feedback regarding routine business transactions, so that managers can monitor operational activities and introduce changes if necessary.
System feedback can be positive or negative. If the system behaviour needs to be altered (reversed) in order for its output to move closer to the desired state, then we have a negative
feedback loop. Two examples are the way a singer adjusts the tone of her voice so that it is in harmony with the orchestral instruments or the correction that we apply to the steering wheel if the car moves slightly out of its lane. However, if the feedback loop reinforces the current behaviour of the system, then we speak of positive feedback, such as when a student achieves good marks after studying hard for a test. Consider a small boy throwing a tantrum: his
mother could discipline him by sending him to his bedroom, or could pacify him by giving him a sweet. Which of these would be positive and negative feedback, and why?
The study of how systems can be controlled, with a particular focus on automatic or self-controlling systems, is called cybernetics. Although it initially arose from engineering, it is now considered to be a sub-discipline of general systems theory.
3.3 Systems Concepts
When analysing systems and their interaction with the environment, a number of useful
concepts should be borne in mind.
3.3.1 Open vs Closed Systems
Any system that interacts with its environment is called an open system. There is in reality no such thing as a closed system, which would have no inputs or outputs and therefore, in a sense, no environment. Nevertheless, some systems are mainly self-sufficient whilst other, more open systems have a much greater degree of interaction with their environment. It is important to cater for this interaction with the environment when planning any system – there would be no point in starting a business that manufactures top quality goods, if you have no way of delivering them to your potential customers, or if you do not have access to the raw materials that you need!
3.3.2 Dynamic vs Static Systems
A dynamic system is a system that has at least one (and usually many) activity or process; as opposed to a static system, which has no activity, whatsoever. Again, there are very few completely static systems and we typically use these concepts in a relative sense: we refer to one system as being more dynamic than another, more static system. The more dynamic a
system, the more flexibility must be built into the inter-relationship of components, allowing 26 [Free reproduction for educational use granted]
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them to function in different ways as activities change – especially important in a modern business environment.
3.3.3 Continuous vs Discrete Systems
A continuous system is a system where inputs (and outputs) can be varied by extremely small amounts or quantities. Discrete systems are systems where the inputs or outputs can take on only certain discrete or distinct values. A traffic light ( robot) is a discrete traffic signalling system because its three lights (green, amber or red) are either on or off. It remains discrete, even if we extend the number of signals e.g. some lights can be switched on
simultaneously (as in England where a simultaneous amber and red light indicate an imminent change to green) or allow for flashing lights (to indicate malfunction or during night-time operation). A mercury-based thermometer, like many physical systems, is a continuous
system as the level of mercury rises or falls gradually along with imperceptible fluctuations in the environment’s temperature. Many electronic systems are a combination of both e.g. a
digital thermometer has a sensor that records temperature as a continuous input but displays a temperature reading which has been rounded to the nearest degree.
Discrete systems have clearly identifiable states. The traffic light is either green or not when you cross the intersection; there is little use in arguing with the traffic officer that it was still a little bit green! A continuous input or output is often converted or approximated to a nearly continuous but actually discrete measure, such as when we measure a temperature to the
nearest tenth of a degree or time the finish of an athlete to the nearest hundredth of a second.
This enables us to model the real, physical world with electronic equipment such as
computers, which can work only with finite precision (i.e. discrete) numbers. A good example of how well this conversion process can work is the Compact Audio Disc recording system
which samples the music many thousands of times a second and converts the frequency of the sound signal at each time point into an integer number between 1 and 60000.
3.3.4 Structure and Hierarchy
The interactions between the various sub-systems and components of a system display some pattern or regularity. In this sense the observer can identify certain relationships, which contribute to the overall behaviour of the system. The entire set of relationships is referred to as the structure of the system. In a purely physical system, the physical location of the components and the connections between them will account for most of the structure e.g. the way the various parts of a car are joined together would account for its structure. In systems that involve informational and conceptual components, the structure will be much less
tangible and involve some level of abstraction e.g. when you try to identify the social
structure of an extended family unit.
Often, components of a system can be regarded as smaller systems in their own right. These are called sub-systems of the system under consideration and the latter probably constitutes most of their environment. These smaller sub-systems are thus embedded within the system, which in turn may be a sub-system of yet another, larger system: the supra-system. This nesting of systems within systems within systems is referred to as a system hierarchy. A common example is the physical universe (the ultimate physical supra-system), which is
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made up of galaxies (our Milky Way is one), which in turn consist of solar systems (e.g. ours with the familiar sun at the centre), which contain planets (including the planet Earth with its moon). Our planet Earth consists of a biosphere which contains all living things, including human society, which is in turn made up of social sub-systems or cultures, made up of
humans (biological systems), made up of cells, in turn consisting of complex molecules etc.
all the way down to the basic building blocks of matter (currently quarks). Another example is a large multinational organisation (one system, whose super-system is the international
political economy) which may consist of various national companies, who in turn have
regional branches or establishments, which may consist of various departments or project groups etc.
3.3.5 Holism and Emergent Properties
The chemical behaviour of one molecule of water (H2O) is very different from the behaviour of large amounts of them when they make up an ocean. The inorganic chemist will have little to share with the wave surfer, art photographer or scuba diver about the properties of water.
We are also familiar with the fact that the actions of a large mob or crowd may be very
different from the behaviour of any individuals making up the mob. And of course the
psychological and emotional behaviour of an individual can not be understood from the
perspective of (or reduced to) his biological make-up i.e. his cell structure.
The perspective from which claims that many aspects of a system can be understood only in terms of its entirety, and not necessarily be reduced to the characteristics of its components, is called holism (the opposite of reductionism). This is often expressed in the popular saying that a system is more than the sum of its parts. Holism also implies that it is important to be aware of the inter-relation between the various components of a system: everything is related to everything. When a person is ill, traditional medicine will look at the symptoms of the patient, diagnose the illness and prescribe some medication which will cure the patient by relying on some type of biochemical reaction within the body of the patient. The holistic approach will look at the lifestyle of the person, her emotional well-being and any
psychological factors which may have contributed to the illness, i.e. a much wider perspective is taken, and illnesses are viewed in the context of the individual as a social, psychological and biological system.
The holistic systems view implies that a system has certain properties, qualities or attributes which cannot be reduced to or understood from its components alone. These properties are called the emergent properties of a system. Examples of emergent properties are the corporate culture of an organisation, the consciousness of a living individual, the feel of a car, the atmosphere or vibe of a pub, the cultural identity of a social group.
3.3.6 Entropy
An important measure of a system is the amount of order (in the case of matter or
information) or potential energy it contains. The measure for disorder or energy degradation is entropy: the higher the level of disorder, the higher the entropy level. All systems change over time and, unless a system can draw on resources from the environment, it will tend to become more disorderly or lose energy (“run down”) i.e. entropy increases. This is one of the 28 [Free reproduction for educational use granted]
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systems fundamental laws; it is a generalisation of the second law of thermodynamics, which states that the energy in the universe degrades irreversibly as time passes.
The concept of entropy is a fairly difficult one to understand conceptually. Though it is possible to define it more rigorously (i.e. mathematically!) the following examples illustrate the essence of the concept. A hot plate of food or an ice-cold drink placed on the table will tend to take on the ambient room temperature. A spring-driven clock or watch will slowly unwind and stop. A house or garden that is not maintained will slowly become more and more disorderly. Music or video signals on a magnetic tape will slowly fade away until, after many decades, nothing but noise remains. As a log fire keeps radiating heat and light energy, it slowly cools down until nothing but ashes remain. In every one of these examples, the input of energy serves to restore the system temporarily to a lower level of entropy (although this usually implies an increase in the overall entropy of the supra-system).
3.4 South African Perspective
Careful analysis of an intended system (its inputs, outputs, interfaces, processes etc) can prove invaluable in identifying unforeseen problems at the planning stages. Apparently this did not happen in the case of the renovation and expansion of the facilities served by the upper cable station on Table Mountain – no process was included to dispose of the increased volume of sewage that resulted, until a major problem had become apparent!
Until the end of 2001, a mixture of partially treated sewage from lavatories and waste water from the restaurant’s sinks and dishwashers was allowed to seep down the mountain, killing vegetation and causing an outcry among environmentalists. Since then, effluent has been
stored in a tank on the summit and is removed by cable car, but with the expansion of
facilities and increasing numbers of visitors, the cableway company is concerned that this is not a sustainable solution.
3.5 Beyond the Basics
A number of system rules, which have been developed based on general systems theory, are particularly relevant to business. Examples of these are:
• Law of requisite variety: Control can be obtained only if the variety of the controller is at least as great as the variety of the situation to be controlled. In other words, every possible situation should provide feedback, which can be acted upon if required; this
can be applied to controllers ranging from smoke detectors to computer error
messages.
• Law of requisite hierarchy: The weaker and more uncertain the regulatory capability,
the more hierarchy is needed in the organisation of regulation and control to get the
same result – where systems (or people) are not self-regulating, then strong
management supervision becomes essential.
• Sub-optimisation: If each subsystem, regarded separately, is made to operate with
maximum efficiency, the system as a whole will not operate with utmost efficiency. In
practice, the goal of the entire organisation must be the first priority, even if this is achieved at the expense of some projects or departments.
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• 80/20 principle: In any large, complex system, eighty per cent of the output will be
produced by only twenty per cent of the system. This applies to people, equipment,
products, etc, and it is worth trying to identify the most productive 20% to make sure
that it continues to function effectively.
• Redundancy of resources principle: Maintenance of stability under conditions of
disturbance requires redundancy of critical resources. So make sure that you have
spare parts for critical equipment, and staff who are able to fill in if a key employee is off sick!
• The environment-modification principle: To survive, systems have to choose between
two main strategies. One is to adapt to the environment, the other is to change it. And
after all, changing the (customer) environment is what marketing is all about.
3.6 Exercises
3.6.1 Systems concepts
Consider the following two systems:
1.
McDonalds hamburger franchise in Rondebosch
2.
A large hospital, e.g. Groote Schuur
• Give examples for each system of the system goal or purpose, 2 inputs, 2 components, 2 processes, 2 outputs, one sub-system, one supra-system and an external feedback
mechanism.
• How would you measure whether the entropy of each system increases or decreases?
3.6.2 Systems Thinking
“Systems thinking” refers to trying to solve problems by looking at their wider context, and examining the root causes, interactions, feedback mechanisms, etc.
• Think of an example of a problem that cannot be solved effectively by addressing
only its apparent symptoms, and explain why this is the case.
3.6.3 The Systems View
Make a list of at least 10 different systems that you are a part of in everyday life.