Technodiversity Glossary

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The term "degree of mechanization" is commonly used, but the content of this term varies extremely. After a long discussion, the authors of "Technodiversity" have agreed to the following, complex definition:

In case of one single subprocess 

It can have three degrees:

• Manual work: Everything is done by human or animal, as a maximum a hand tool is used.    
• Motor-manual work: The energy is coming from a machine that is handled by  a human. Thus, the weight is limited. Typical examples are the work with a chainsaw or with a brush-cutter. 
• Mechanized work: When the machine is self-propelled, the limitation of the weight is much lower. As a consequence the machine can have more power and can be optimized for the task. Mechanized work can be subdivided into several steps:

  • Simple mechanized work offers increased power and mobility, but all auxiliary functions are done by humans. Example: a cable skidder can move larger loads than a human can, and does that at a higher speed. But the attachment of the logs must be done manually by the operator.

  • When the machine also takes over the auxiliary function to handle the object by means of a crane or a grapple, e.g., but all actions must be steered by the operator, we call it advanced mechanized work. A typical example is a tractor or forwarder equipped with a loader.

  • Actually, mechanized work is developing more and more towards automatic work. We like to subdivide 4 steps of automation:

    • information assistance (by sensors)
    • control assistance (by electro-hydraulic control, e.g.)
    • automation of sub-processes
    • driverless operations

    In forestry, the cut-to-length harvester is an example of a machine that reaches the level automation of sub-processes. Some prototypes try to operate driverless.

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In case of two sub-processes:

Normally, a total harvesting process is a combination of two or more sub-processes. Since each sub-process has its degree of mechanization,  we want to characterize the total process by a degree of mechanization, too. 

This is easy, if the degrees are equal. Then we have a fully manual, a fully motor-manual, or a fully mechanized method. 

If the degrees differ, we take the name of the highest degree and add the adjective "partly". 

"Almost fully mechanized":

In some cases, we need a more differentiated description. Let's explain it with an example: When the distance between trails is wider than 20 m, the harvester that is instructed to stay on the trail cannot fell all trees, because its crane is not long enough. In that case a worker with his chainsaw fells those trees beyond harvester reach towards the trail. Later, the harvester picks the full trees up and processes them.

Here, the most important machines are harvester and forwarder, forming a fully mechanized method. But due to the felling with chainsaw as an additional sub-process, the degree of the total process would turn to partly mechanized. We have the feeling that does not well represent the reality. Consequently, if the sub-process with the lower degree of mechanization is only necessary for a smaller subset of working objects, we can express it with “almost fully mechanized”.

Depreciation is a part of the cost calculation with the engineering formula. It considers the loss of value of a working system during its life span.

Imagine you plan to buy a machine. It is very expensive, so the decision should be made carefully.  If you intend to get a loan from the bank, you need a plan to pay the money back within a certain time. That means: Hour by hour you must put aside a certain sum, which you will transfer to your bank at the end of the month.We call this depreciation.

The lifetime of a tool or machine is limited. There are several reasons for decay:

•       Technical decay (obsolescence) depends on technical progress: when new and better machines appear, your old machine may be no longer competitive.

•       Technical aging (wear) happens when parts of the machine become thin, stiff, inflexible, and break, i.e.

•       In some situations, we have only limited use of a machine, afterwards we will not need it any longer.

•       Or the machine suffers from a “fashion change”, when your technology will become unfashionable, and nobody will be interested in this technology any longer.

Depreciation is the response to the progressive loss of value of your machine. During this time, we must pay back the initial investment.

If we did not borrow the money from the bank, we have taken it from the “investment pool” of our company. We have only changed money into a machine with the same value. When the value of the machine decreases, we must pay back into this pool in order to stay as “rich” as before.

A third argument for depreciation deals with taxes:

Since the taxes are based on the win, we should not forget the hidden costs by the daily devaluation of our equipment.

How do we calculate depreciation?

•       First, we decide how many years the machine will be used.

•       Then we ask, whether it will be possible to sell the old machine at the end of the utilization time. But be careful there! Normally there is some residual value, but we may want to assume that it is 0 and use it as a silent reserve to compensate the higher price for a new machine – due to inflation and technical development.

•       The annual depreciation now is calculated as the initial investment minus the assumed residual value divided by the number of years.

This is called linear depreciation. In fact, real devaluation is not linear (here implied with red or green) but in practical term a linear solution is good enough and it is easier to calculate.

(See more at TDiv PR1-C02)

Ergonomics follows a very simple basic model that derives from physics: When you impact a body with a certain stress, the body will react with a corresponding strain. Since a standard method causes a stress that is typical for this standard method, the strain as a reaction to this typical stress situation should be typical, too.

The intensity of the strain, however, is not the same. It depends on the worker: his personal attributes, his abilities and his skills (together they form the capability for work). And it varies due to the actual disposition and motivation (together called readiness for work), and his health. If the strain overruns the permanent work load, breaks are necessary for his personal recovery to avoid acute or chronic damage.

We know that there are days when the same job feels hard, and days when it feels much easier. So, for the same individual the strain can differ. This partly depends on the health, conditioning, tiredness, hunger and time of the day. We call these organic reasons disposition.

(See more under TDiv PR1-E04)