Below is a general statement of six perspective tasks to optimize reconstruction of a facility in operation. For these optimization tasks do not yet exist means of their solving.

     Here we use the following notations:

• FO — facility in operation, subject to reconstruction;
• EF — element of this facility (its component), which performs a specific function;
• RO — reconstruction operation: a set of elementary operations, called the stages, on creation of the new EF or on modernization or liquidation of the old one;
• RS — reconstruction scheme: a network graph with initial and final nodes, which describes the order of reconstruction execution;
• OPFR — optimal (best) plan of FO reconstruction, which will be synthesized;
• HPFR — heuristic plan of its reconstruction, which will be specified for an objective evaluation of OPFR efficiency.

     Given:

• RS, that is described by the following parameters:
  • number of ROs;
  • number of stages in each RO;
  • links between stages, as well as their types (serviced and switched ones);

Note. The condition for permissibility of executing any stage is the presence of all executed stages, entering into its initial node.

• array of fines per time unit for the loss of FO functionality in connection with the execution at this moment of a particular set of ROs;
• for each serviced stage of each RO are given:
  • number of stage execution options, each of them is represented by three parameters:
    • execution duration;
    • run-time;
    • a sign of blocking the execution interruption;
  • basic option of executing the stage, that refers to HPFR;
  • duration of a minimum time slot, called time increment (several days, one week or one month), in which will be given all time parameters;
  • permissible value of expenses for executing all reconstruction operations during a one time increment;
  • for HPFR: priorities of executing different ROs, as well as possible additional blockings of simultaneous executing several ROs;
  • a fine per time unit for staying the FO in state of its reconstruction;
• restriction for optimizable process:
  • for tasks 2 and 4 — permissible time of FO reconstruction;
  • for task 5 — permissible cost of FO reconstruction, which is the allowable amount of expenses for direct execution of all works on FO reconstruction;
  • for task 6 — permissible cost of all penalties.

     Minimized quality criterion (one of three possible):

1)   total losses on reconstruction, including the costs of FO reconstruction and all penalties (effect of specified fines for the loss of functionality of the FO and its reconstruction), at one of two possible restrictions:

• • for task 1 — without restriction;
  • for task 2 — permissible time of FO reconstruction;

2)   cost of all penalties at one of three possible restrictions:

• • for task 3 — without restriction;
  • for task 4 — permissible time of FO reconstruction;
  • for task 5 — permissible cost of FO reconstruction;

3)   for task 5 — cost of FO reconstruction at the following restriction: permissible cost of all penalties.