 1.

Specifying the analyte and measurand
 2.

Choosing a suitable measurement procedure with associated model equation
Model equation
Calculation of water content in sample is carried out according to the following equation (mathematical model):
$$ c_{\text{water}} = \frac{{V_{\text{t}} \cdot T_{\text{t}} }}{{m_{\text{s}} }} \cdot f_{\text{r}} \cdot 1000 $$
(13)
c_{water} is concentration of water in oil sample [mg/kg], V_{t} is volume of titrant used for titration [ml], T_{t} is the titer of the titrant (mass of water per unit volume of titrant) [mg/ml], m_{s} is the sample mass [g], f_{r} is the repeatability factor, 1000 [g/kg] is the unit conversion factor. The reason for inclusion of f_{r} is the following: the amount of injected sample is measured gravimetrically and each time the sample amount is slightly different. Thus, the repeatability components of V_{t} and m_{s} are not included in the uncertainties of these quantities but are taken into account separately by the repeatability factor f_{r}.
 3.

List the input quantities according to their influence on the uncertainty of the result of the measurement (first the most important ones). At this point, your judgement should be based on your previous experience only
 4.

List the reference standards needed and give also the information regarding traceability of the reference value
For the other input quantities  5.

Estimating uncertainty associated with the measurement
 6.

How would you prove traceability of your result?
 7.

Any other comments, questions…