Robert J Morton
Robert J Morton |
Before we can embark on an activity analysis of the home we need a proper 'engineering definition' of what an activity is.
The dictionary defines activity as "exertion of energy...". It also defines energy as "force of action; active operation...". So it defines activity in terms of energy and then defines energy in terms of activity.
Defining one word in terms of another is ultimately like trying to climb up on your own shoulders to see over a high wall. The Dictionary of Words has to assume that you already know at least some words to start with. So where do you go to look up the meanings of those first words? The only place you will find them is in the Dictionary of Experience.
We all somehow know what is generally meant by the word activity. An activity is something we do or take part in. We must have at some time been doing something alone or with others when someone referred to what we were doing as an activity. We learned that the word activity applied to that experience. That particular activity will also have had a specific name like football or tidying the bedroom. So we learned also that the word activity applies to a number of things that we do or take part in. It refers to what we call a class of things.
This class of things which we have already experienced, to which we attach the word activity, provides the frame of reference against which we judge any new thing to be or not to be a member of that class. But all we have done is learn to identify an activity: we have not defined in engineering terms what an activity is. To do this we must look deeper into the Dictionary of Experience.
Lower your body by bending your legs. Then spring your legs straight forcing your body upwards against the pull of gravity so that you leave the ground and move slightly above it. The force of gravity then rapidly reduces your upward velocity until it decreases to zero and reverses. You then accelerate towards the ground until your feet make contact with it again. Then let your legs bend again using your leg muscles to absorb your downward motion until your body is low down again. Repeat until you get tired.
This is one way of describing the activity called jumping up and down. A more mechanistic way of describing the activity of jumping up and down could be:
Of course the activity of jumping up and down in reality involves vastly more complex processes within the body than has been described here. Nevertheless, this description is complete and accurate at the depth or resolution to which it goes.
The seven steps above are referred to as a procedure. A procedure is a necessary element in the engineering definition of an activity.
An activity also has a purpose or objective. The objective in jumping up and down is perhaps to exercise your body.
Some activities require more than one person. Some require specific facilities, tools and equipment as well as an environment. Facilities, tools and equipment merely extend human limbs and senses to enable one to perform a specialised action quicker, more precisely or more powerfully.
An example of an activity is jumping up and down. A person is required to do the activity, and the necessary environment is any firm area on the surface of the Earth - or any other planet with adequate gravity.
In summary, therefore, an activity is:
and an activity requires:
Various ducted services may also be required to enable the human being and the equipment to operate. The result of the activity is its output. This usually takes the form of a product or service such as a meal or the washing of clothes.