What is a System?
Systems are an inter-disciplinary term, and have different definitions in different fields. Electrical engineers build power systems. Integrated circuit designers build electronics systems. Doctors study human systems, such as the nervous system or digestive system, and apply that knowledge to treat individuals. The definition of a system, if it is cover all these scenarios, would be a set of elements that work together to accomplish a defined objective.
3.1 What is a system?
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Systems are an inter-disciplinary term, and have different definitions in different fields. Electrical engineers build power systems. Integrated circuit designers build electronics systems. Doctors study human systems, such as the nervous system or digestive system, and apply that knowledge to treat individuals. The definition of a system, if it is cover all these scenarios, would be a set of elements that work together to accomplish a defined objective.
Information systems consist of people and technology working together to extract, transmit, store, retrieve, manipulate, and display information. Effective information systems are designed with an understanding of how users interact with them, and how systems interact with each other. The formal boundaries of a system are defined through the combined experiences of those who use the system. A designer has to understand the environment where the system would exist, and needs and expectations of the users of the systems. The best IT systems just seem to "fit" into their environment, where users intuitively grasp their role and use them as if they have always been using them. This section provides some examples of how users experience systems in a modern world.
The modern urban dweller interacts and experiences different systems numerous times in the course of a work day. A person wakes up to a room where the electrical appliances are run on power provided by an energy provider. Each electrical appliance, such as the coffee-maker, is a self-contained system with a dependency on the energy provider, and is contained in a kitchen. The plumbing in the bathroom is connected to a sewage system. Public transporation systems provide the means to get the person to work. People interact in different ways with these systems, and their expectations are shaped by their experiences with these systems. Let's consider some examples of how user experiences define systems.
“The cup of coffee was just right this morning.”
In its lifetime, a good coffee-maker will produce several cups of coffee. Given consistent inputs (water, beans, power, filters), most coffee machines will produce consistent results. Drinking a cup of coffee is how the user experiences the coffee, and the nature of the experiencde can vary from day to day. The quality of the coffee is a very important factor in defining the experience, but several other aspects influence the user's experience on any given day: whether the kitchen was in a mess or was in a pristine state that morning; whether the person was in a rush or had plenty of time to drink the coffee; whether the person drank the coffee alone or in the company of others. A cup of coffee being just right is dependent on all of these factors. The utilization of the machine is beyond the control of a designer, but the designer can influence how users will interact with the system. For machines that provide low volumes of coffee, the user can manually feed the input materials (water, beans), and the dispensing area can contain room for a single cup. For machines that produce higher volumes, the water supply can be plugged directly into the plumbing system, larger containers can be used to feed the machine, and the dispensing area can contain several slots for different sizes of containers.
Figure 1: A coffee maker
The System: A machine that can product a hot cup of coffee
The User: A person who wants some coffee, and perhaps depending on how early it is, sorely needs it.
Roles: Coffee-drinker (the user whose perspective we are considering), Coffee-Maker (a machine in this case)
The Environment: Typically used in a domestic environment with other household appliances.
Dependent system(s): Water and Power supply, Waste management system
Service Expectations: Given fixed inputs, the machine should produce a hot cup of coffee within 2 minutes.
The experience: The coffee machine is located in the kitchen. Coffee cups are located in a nearby storage area. The coffee machine will dispense black coffee, and the user will add milk and sugar to taste.
Exceptional scenarios (some undesirable): Input materials not available (coffee, milk, sugar, water, electricity);machine does not work as expected;machine is used beyond its capacity
Unbalanced forces (beyond the system's scope, but influences the experience): The kitchen is dirty; The person is in a rush; The person is not have the pleasure of regular company.
"The 8:04 bus from Main Street was on time this morning."
What is the "8:04" bus in this sentence? The statement seems to imply that the "8:04 bus" is a physical object. However, every morning, one of the several buses within the city's fleet can be the "8:04 bus" from Main Street. The bus drivers can be different each morning. We continue to experience the 8:04 bus in a consistently as any of the buses or drivers will follow some similar patterns. The buses are usually the same color. The drivers usually wear the same uniforms. The bus usually follows the same route and should leave the bus stop located in Main Street at 8:04 every morning.
Figure 2: A bus arriving at a bus stop.
The "8:04 bus from Main Street" follows some common patterns, and these common patterns define a system for the passengers who board the bus at Main Street. For passengers that board the bus at the next stop, the bus becomes the "8:10 bus from Harley Street". Each group of passengers experience parts of a more comprehensive logistics system, but the passengers do not need to understand the entire system to use its services. It is sufficient for passengers to understand the concepts of timetables, bus routes, that buses that travel on a route have a bus number, and that a fare is charged for the transporation service. The bus being "on time" this morning indicates expectations from passengers about the quality of service provided by the bus: The bus should not leave before 8:04 am; the bus should halt at Main Street for a sufficient duration, giving passengers time to board the bus; the bus should not be late. The expectations on the service quality isn't usually something a public transport company provides. Usually, it amounts to "we'll try our best, and we hope that is good enough". In most cases, their best effort is usually good enough. The duration a person is willing to wait for the bus is entirely up to the person and their situation.
The System: A public transportation system
The User: A person who wants to travel from a start point to destination within a fixed period of time
Roles: Passenger (the user whose perspective we are considering), Driver, Conductor (role can be performed by the same person who is the driver provided a low number of passengers)
The Environment: A public area where any member that can pay the bus fare can use the logistics services offered by the transportation system.
Dependent system(s): Road network, Ticketing systems, Payment Systems, Energy Systems, Vehicle Support Systems, GPS Systems
Service Expectations: The bus should leave a bus stop at the scheduled departure time. The bus should arrive a few moments before the schedule time at the bus stop. The bus should hat at the bus stop for a sufficient duration.
The experience: A passenger waits for the bus at the bus stop. The bus arrives a few moments before the scheduled departure time. The bus stops, and the passenger boards the bus. The passenger can either purchase a ticket, show the bus driver an existing ticket or bus pass, or be exempted from requiring a ticket. The passenger finds a seat, and sits down for the duration of the journey. The passenger arrives at their destination at the scheduled time, and disembarks from the bus.
Exceptional scenarios (some undesirable): The passenger is late, and arrives to miss the bus; the passenger is late, and just catches the bus (a very satisfactory experience); the bus is late; the bus driver fails to stop at the bus stop; the passenger does not wait for the bus and uses an alternative; the bus is full and cannot accomodate any more passengers; the passenger does not have any form of payment for the bus; the bus driver is unable to accept payment due to failure of the payment system; the passenger cannot find a seat and has to stand; the passenger is injured during the journey; the bus has an accident; the bus has a malfunction and stops functioning completely; a component of the bus has a malfunction (e.g. the airconditioning stops working); the bus driver is incapacitated during the journey; the bus driver deviates from the route (perhaps because he is not familiar with the route); there is an altercation in the bus between people in the bus; the bus arrives late in the destination.
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