The fixed asset theory, when viewed as an investment/disinvestment theory, implies a simple two-parameter control-limit decision rule. The theory is extended to incorporate the stochastic nature of farm revenue. The results show that ongoing uncertainty leads to a widening of the range of inaction because there is a positive value of waiting. The effects of sunk costs, or the divergence of acquisition costs from salvage values, on the degree of investment/ disinvestment irreversibility become more pronounced when uncertainty is present.