Definition
In an economy with L commodities, a production vector (or input-output, net input, vector, production plan) is a vector 
that describes the (net) outputs of the L commodities from a production process.
indicates output
indicates input
In convention, positive numbers denote outputs and negative numbers denote inputs.
Elements of a production vector may be zero: the process has no net input of that commodity.
Note
- Note that elements of production vector are the net output of a production process, that explains the negative value for inputs.