Modelling (pre-)Design Activities With a Multi-Stakeholder Perspective - Principia Designae: Pre-Design, Design, and Post-Design - page 181

Table 12.3 Example processes occurring in the early stage of design of a kettle, classified according to the proposed extended FBS model
Design phase Process From To Process

Needs
identification

I:
Ne ! N i

No maintenance Avoid impairing the following usages I:

Ne ! N i

Avoid formation of deposit

II:
N i ! R i

Avoid impairing the following usages Subsequent usages of the kettle do not create variations

of the boiling time, as well as of the chemical/physical
or organoleptic features of water

II:
N i ! R i

III:
Re i ! Ne i

The hardness of water boiled in the kettle should not
increase more than 5 mg/L, nor the poured water should
contain particles bigger than 0.2 mm

Invariant water taste and healthiness III:

Re i ! Ne i

No visible deposit inside the poured water

IV:
Ne i ! Ne

Invariant water taste and healthiness Boiled water should not impact the taste of the

tea/coffee

IV:
Ne i ! Ne

Safety of boiled water after years of usage