JP2019197538A - Ship assignment plan creation method, operation method by the method, and ship assignment plan creation device - Google Patents

Abstract

To provide a ship assignment plan creation method capable of creating a ship assignment plan in consideration of achieving both stable supply and minimized transportation cost of materials from a plurality of points of loading to a plurality of points of discharge by a method that does not need simulation.SOLUTION: A ship assignment plan creation method includes calculating discharging time at each point of discharge and a discharging amount for each discharging on the basis of inventory upper and lower limit values without considering constraint on transportation by a ship, creating a temporary navigation pattern determining loading materials and loading amounts at each point of loading of a navigation path pattern and discharging materials and discharging amounts at each point of discharge on the basis of calculation results, creating a plurality of navigation patterns on the basis of the temporary navigation pattern, and selecting a navigation pattern used in a ship assignment plan on the basis of excess or deficiency from the inventory upper and lower limit values and transportation costs from the plurality of created navigation patterns.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a ship allocation plan creation method, an operation method using the method, and a ship allocation plan creation apparatus.

  When transporting raw materials by ship, it is important from the viewpoint of stable supply and reduction of transport costs to properly develop a transport plan that determines the ship to be used, the goods to be loaded, and the route of the delivery destination. In particular, factories that manufacture products from raw materials that have been transported must be transported from the raw material supplier's site so that raw material stock can be secured, so a stable supply is required. However, as the types of raw materials handled, loading and unloading factories increase, the transportation plan becomes complicated and it becomes difficult to plan transportation cost reduction. In order to solve such problems, various planning methods using optimization techniques such as mathematical programming and metaheuristics have been proposed.

  Steelworks, one of the application fields of the above method, produce steel products using raw materials that have been transported from overseas every day. In order to stably produce high-quality products, it is necessary to adjust components by blending a plurality of raw materials, and it is necessary to stably supply a plurality of raw materials to a steel mill without cutting them. On the other hand, it is also necessary to reduce the transportation cost of raw materials. It is necessary to create an appropriate transportation plan (ship allocation plan in this project) in order to balance the quality and transportation costs. The transportation cost includes the dredging cost of the ship and the berthing fee that is paid to the ship owner when it takes more days than the contracted schedule.

  There are multiple raw material supplier ports (loading sites) overseas, and one brand is loaded with different brands of raw material at one or more loading points. There are multiple landing sites to which raw materials are supplied, and these are also unloaded at one or more landing sites in a single voyage. A single loading site can be loaded with different types of brands. The ship that carries the voyage uses a bulk ship that has divided parts for loading. Bulk ships come in several sizes, each with a different capacity and dredger cost. Also, there are two types of ship contracts, and one dedicated ship is a ship that has signed a contract for a long term and needs to be used with priority. The other is a spot ship that is arranged on every voyage. In general, several voyages are performed several hundred times a year, and for each voyage, the date of allocation / ship used / loading place / loading brand / loading schedule and the landing site / shipping brand / loading volume are determined. It is necessary to decide the schedule at the landing site. Thus, since it is necessary to consider both loading and unloading schedules, there are many decision items that are variables, and the possible combinations are enormous. Enumerating a large number of combinations cannot be calculated in a practical time. Therefore, various planning methods using optimization techniques such as mathematical programming and metaheuristics have been proposed in order to obtain an optimal solution from the viewpoint of stable supply of raw materials and reduction in transportation costs.

  For example, in Patent Document 1, the operation sequence of each means of transportation and the type of goods to be transported, and the simulation for calculating the arrival date and the arrival amount for each kind of each article based on the settings are repeatedly executed, and metaheuristics is used. Have created an optimal logistics plan. Moreover, in patent document 2, after creating the mathematical model which expresses the combination pattern of the loading place and the landing place which can be operated for every ship, and the supply-and-demand balance restriction in the landing place, after performing optimization calculation using mathematical programming, The ship planning is planned in detail by simulation.

JP-A-11-310313 Japanese Patent No. 4669583

  However, in Patent Document 1, there is only one landing site for one voyage, and no consideration is given to unloading at a plurality of landing sites. Moreover, in patent document 2, after execution of optimization calculation, the simulation that the cargo handling of a ship does not overlap on a berth is implemented. Therefore, the simulation result of changing the cargo handling time of the ship so as not to overlap may deviate from the result obtained by the optimization calculation, and the balance between supply and demand may deteriorate. In particular, when there is no margin in the capacity of the berth, there is a risk that the possibility of the deterioration will increase and the stock will run out.

  Accordingly, an object of the present invention made in view of the above problems is to achieve both stable supply of raw materials from a plurality of loading sites to a plurality of landing sites and minimization of transportation costs in a method that does not require simulation. It is an object to provide a ship assignment plan creation method capable of creating a ship assignment plan in consideration of the above, an operation method using the method, and a ship assignment plan creation apparatus.

  In order to solve the above-described problem, a ship allocation plan creation method according to an embodiment of the present invention is a ship allocation plan for planning a schedule for transporting a plurality of brands of raw materials from a plurality of loading points to a plurality of landings. Raw material information including stock amount and stock upper and lower limit values of each raw material for each landing site, landing site information including cargo handling efficiency related to berth for each landing site, and loadable raw material for each loading site A data reading step for reading information relating to ship allocation plans including ship location information including the amount of loading information, vessel capacity to be used and shipping cost, and the upper and lower limits of inventory without taking into account restrictions on shipping by ships Based on the value, the required unloading calculation step for calculating the unloading timing and the unloading amount at each landing at each landing site, and the loading material and loading at each loading site of the route pattern based on the calculation result of the necessary unloading calculation step And a provisional voyage pattern creation step for creating a provisional voyage pattern that defines the unloading raw material and the amount of discharge at each landing site, and a plurality of voyage patterns based on the tentative voyage pattern, And a voyage pattern creation / selection step of selecting a voyage pattern to be used in a ship allocation plan based on excess and deficiency from the upper and lower limits of the inventory and the transportation cost.

  Moreover, the operation method which concerns on one Embodiment of this invention is characterized by operating a steelworks using the ship allocation plan created by said ship allocation plan creation method.

  Further, a ship allocation plan creation device according to an embodiment of the present invention is a ship allocation plan creation device for planning a schedule for transporting a plurality of brands of raw materials from a plurality of loading points to a plurality of landing sites. , Raw material information including the stock amount and stock upper and lower limit values of each raw material for each landing site, landing information including the cargo handling efficiency for the berth for each landing site, and product including the amount of loadable raw material for each loading site Based on the above-mentioned inventory upper and lower limit values, without considering the data reading unit that reads information related to ship allocation planning including ship information including land information, ship capability and transport cost, Based on the calculation result of the required unloading amount calculation unit for calculating the unloading timing and unloading at the landing site, and the calculation result of the necessary unloading amount calculation unit, the loading material and loading amount at each loading point of the route pattern and each landing point The raw material and amount of unloading A temporary voyage pattern creation unit for creating a temporary voyage pattern, a plurality of voyage patterns created based on the tentative voyage pattern, and the excess and shortage from the inventory upper and lower limit values and transportation from the created voyage patterns And a voyage pattern creation / selection unit that selects a voyage pattern to be used in a ship allocation plan based on a cost.

  According to a ship allocation plan creation method, an operation method according to the method, and a ship allocation plan creation apparatus according to an embodiment of the present invention, a stable supply of raw materials to a landing site and transportation costs can be achieved by a method that does not require simulation. It is possible to create a ship allocation plan that takes into account minimization.

It is a block diagram of the ship allocation plan preparation apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the ship allocation plan preparation apparatus which concerns on Embodiment 1 of this invention. It is the information which shows the stock quantity and consumption of each brand in each landing. It is information which shows the storage capacity in each landing site. This is information indicating the maximum efficiency (1,000 tons / day) of each berth, the cargo handling efficiency (1,000 tons / day) on each day, and the berth unusable date. This is information indicating the hatch size and the number of hatches for each ship size. It is information which shows the port size which cannot enter a port in each loading place and each landing place. This is information indicating the loadable amount of each brand. It is information indicating the number of days of voyage from Japan to each loading site. It is the information which shows the number of days of voyage between each loading place. It is information indicating the number of days of voyage between loading and unloading sites. It is information indicating the number of days of voyage between each landing site. It is information which shows the handling days in each loading place. This is information indicating the ship size, scheduled voyage end date, DES rate, DEM rate, and fried run of each dedicated ship. It is information indicating the ship size, dredger cost, DES rate, DEM rate, and fried run of each spot ship. It is the information which shows the required unloading amount in each elapsed days. It is the information which shows the required unloading amount in each request period. It is the information which shows the list of route patterns. This is information indicating a temporary voyage pattern. It is information which shows an example of a voyage pattern. It is an example of the ship allocation plan created by the ship allocation plan creation apparatus which concerns on Embodiment 1 of this invention. This is information indicating the type in which brands are aggregated. It is a block diagram of the ship allocation plan preparation apparatus which concerns on Embodiment 3 of this invention. It is a flowchart which shows operation | movement of the ship allocation plan preparation apparatus which concerns on Embodiment 3 of this invention. It is the information which shows the combination of the selected voyage pattern and an exclusive ship.

  Embodiments of the present invention will be described below.

(Embodiment 1)
FIG. 1 is a block diagram of a ship allocation plan creation device 1 according to an embodiment of the present invention. A ship allocation plan creation device 1 according to an embodiment of the present invention includes a database 10, a data reading unit 11, a required unloading amount calculation unit 12, a temporary voyage pattern creation unit 13, and a voyage pattern creation / selection unit 14. Is provided. It is possible to ship a ship according to a ship assignment plan created by the ship assignment plan creation device 1 and to operate a factory such as a steel mill.

  FIG. 2 is a flowchart showing an outline of the operation of the ship allocation plan creation device 1 according to an embodiment of the present invention. As an outline, the ship allocation plan creation device 1 according to the first embodiment devises a schedule for transporting a plurality of brands of raw materials from a plurality of loading points to a plurality of landing sites by ship. In order to formulate the schedule, first, the data reading unit 11 of the ship allocation plan creating apparatus 1 executes a data reading process (step S100). In the data reading process, the data reading unit 11 reads information necessary for creating a ship allocation plan from the database 10. Necessary information is information related to the ship allocation plan creation, and includes raw material information, landing site information, loading point information, and ship information. The raw material information includes the stock amount and stock upper and lower limit values of each raw material for each landing site. The loading site information includes the cargo handling efficiency related to the berth for each landing site. The loading area information includes the amount of material that can be loaded for each loading area. The ship information includes the capacity of the ship to be used and the transportation cost.

  Next, the required unloading amount calculation unit 12 performs a necessary unloading amount calculation process (step S200). In the required unloading amount calculation processing, the unloading time and unloading amount for each unloading at each landing site, which are necessary for keeping the stock of raw materials within the upper and lower inventory limits, are calculated based on the upper limit value of the inventory. Here, the required unloading amount calculation processing does not consider restrictions on transportation by ship (ships used, restrictions on berths, etc.).

  Subsequently, the provisional voyage pattern creation unit 13 executes provisional voyage pattern creation processing (step S300). In the temporary voyage pattern creation process, a temporary voyage pattern is created based on the route pattern. A route pattern represents a combination of routes of ships to be dispatched, and is defined by a combination of unloading time, ship size, loading place, and landing place. The provisional voyage pattern is a route pattern that defines the loading material and loading amount at each loading site and the unloading material and loading amount at each landing site. In the tentative voyage pattern creation process, based on the calculation result of the required unloading amount calculation process, the loading raw material and loading amount at each loading place of the route pattern and the unloading raw material and loading amount at each landing place are determined. Create a nautical pattern.

  Subsequently, the voyage pattern creation / selection unit 14 executes voyage pattern creation / selection processing (step S400). A voyage pattern defines a ship, a berth, and a voyage schedule used in a temporary voyage pattern. The voyage schedule includes the departure date of Japan, arrival date of loading place, departure date of loading place, arrival date of landing place, start date of loading and unloading at landing place, and end date of loading and unloading. In this process, first, a plurality of voyage patterns are created based on the tentative voyage pattern created by the tentative voyage pattern creation process. Then, from among the plurality of created voyage patterns, the voyage pattern used in the ship allocation plan is selected based on the excess and deficiency from the stock upper and lower limit values and the transportation cost. Hereinafter, each process of the ship allocation plan by the ship allocation plan creation apparatus 1 will be described. In the first embodiment, in the required cargo handling amount calculation process, the provisional voyage pattern creation process, and the voyage pattern creation / selection process, processing is performed without considering the possibility of substitution between brands of raw materials. That is, in the first embodiment, the stock amount, consumption amount, loading amount, and unloading amount of each brand are handled as independent ones for processing.

[Data read processing]
The data reading unit 11 of the ship allocation plan creating apparatus 1 reads the plan period (plan start date and plan end date) and each information necessary for creating the ship allocation plan from the user input or the database 10. 3 to 15 show information stored in the database 10. The data reading unit 11 reads these pieces of information.

  FIG. 3 shows information on the stock amount and consumption of each brand in each landing site (lifting site 1, landing site 2,...). The initial stock quantity is the stock quantity of each brand existing on the planning start date (initial state) at each landing site. The stock lower limit value indicates the stock lower limit value of each brand, and it is desirable that the stock quantity of each brand should not always fall below the lower limit value. The stock upper limit value indicates the upper limit value of the stock of each brand, and it is desirable that the stock amount of each brand does not always exceed the upper limit value. Hereinafter, the inventory lower limit value and the inventory upper limit value are collectively referred to as an inventory upper and lower limit value. The consumption amount indicates the amount consumed per day for each brand.

  FIG. 4 is information indicating the storage capacity at each landing site. The upper limit value indicates the maximum value determined from the size of each landing site. FIG. 5 is information indicating the maximum efficiency (1,000 tons / day) of each berth and the cargo handling efficiency (1,000 tons / day) on each day. The date is expressed as the number of days elapsed from the plan start date. The efficiency of cargo handling decreases due to regular repairs of the cargo handling equipment, and the cargo handling efficiency fluctuates. Depending on the type of repair, the ship may not be able to berth (SD (shutdown) period), or may not be able to berth because there is already a plan to berth a raw material ship etc. that is not the target of the plan. It is written as “impossible” in the sense that (unloading is impossible).

  FIG. 6 is information indicating the hatch size and the number of hatches for each ship size. The ship sizes are, for example, a cape size, a Panamax size, and a handy size. In FIG. 6, they are represented as “Cape”, “Panamax”, and “Handy”, respectively. The loadable amount for each ship size is determined by the hatch size and the number of hatches shown in FIG. FIG. 7 is information indicating the size of a ship that cannot enter a port at each loading site and each landing site, and the ship size that cannot enter a port at each loading site and each landing site is indicated by the name of each ship size in FIG. 6. When “None” is shown in FIG. 7, it means that ships of all ship sizes shown in FIG. 6 can enter the port at the loading or unloading site. FIG. 8 shows information indicating the loadable amount of each brand and its place. The amount of each brand that can be loaded and the place of loading are based on the agreement with the supplier.

  FIG. 9 to FIG. 12 are information relating to the number of days of voyage necessary for determining the voyage schedule. FIG. 9 is information indicating the number of days of voyage from Japan to each loading site. As shown in FIG. 9, for example, 10 days are required from Japan to the loading site 1, and 30 days are required from Japan to the loading site 2. FIG. 10 is information indicating the number of days of voyage between loading points. As shown in FIG. 10, the voyage is 3 days between loading place 1 and loading place 2, 5 days between loading place 1 and loading place 3, and 3 days between loading place 2 and loading place 3. It takes days. FIG. 11 is information indicating the number of days of voyage between each loading place and each landing place. As shown in FIG. 11, the loading between loading place 1 and landing place 1 is 13 days, the loading place 1 and landing place 2 is 14 days, and the loading place 2 and landing place 1 is 7 days. It takes 8 days to navigate between Land 2 and Land 2 FIG. 12 is information indicating the number of voyages between landing sites. As shown in FIG. 12, the voyage is 1 day between the landings 1 and 2, 3 days between the landings 1 and 3, and 1 day between the landings 2 and 3. It takes days.

  FIG. 13 shows information indicating the number of cargo handling days in each loading area. FIG. 14 is information indicating the ship size, scheduled voyage end date, DES rate, DEM rate, and fried run of each dedicated ship. The planned voyage end date is represented by the number of days that have elapsed since the planned start date. FIG. 15 is information showing the ship size, dredger cost, DES rate, DEM rate, and fried run of each spot ship. The DES rate, the DEM rate, and the fried run are necessary when calculating the stagnation fee or the early departure fee, and are set to values determined by contract for each ship.

[Required unloading calculation processing]
After the data is read by the data reading unit 11, the required unloading amount calculation unit 12 performs a necessary unloading amount calculation process. The necessary amount of unloading is the amount of unloading of each brand necessary for keeping the stock of each brand at a plurality of landings within the upper and lower inventory limits. With this calculation process, it is possible to grasp how much quantity needs to be unloaded at each timing for each brand. Such calculation processing can be expressed by the following line format and can be solved by a mixed linear programming method. This will be specifically described below.

  First, the stock transition of each brand at each landing site is expressed by the following formulas (1-1) and (1-2).

The constraint equation for keeping the stock of each brand in each landing within the range of the stock upper and lower limits is expressed by the following formulas (1-3) and (1-4).

  Moreover, the upper limit shown in FIG. 4 is set to the capacity of the storage place for the raw material unloaded at each landing site. The constraint equation for the storage capacity at each landing site is expressed by the following equation (1-5).

Further, the amount that can be unloaded in one day is limited by the loading efficiency of each berth shown in FIG. 5 and the case where the ship cannot dock. The constraint equation for such unloading equipment is expressed by the following equation (1-6).

  Furthermore, in the required unloading amount calculation process, optimization is performed so as to obtain a solution that minimizes the total number of times of unloading at the landing site. As a result, it is possible to eliminate solutions where the amount of unloading is small and the number of times of unloading is large, such as unloading a small amount every day. First, a variable for counting the total number of times of unloading is defined by the following formula (1-7).

  The total number of times of unloading is the sum of the above-mentioned counting variables for all schedules, all brands, and all landing sites. This objective function is expressed by the following mathematical formula (1-8).

  The required unloading amount calculation unit 12 calculates the required unloading amount based on the above formulas (1-1) to (1-8). FIG. 16 shows information on the required amount of discharge in each elapsed day by the calculation. The information in FIG. 16 indicates how much each brand is needed at which timing and at what timing.

  FIG. 17 shows information based on FIG. 16, which is a collection of information on the required daily discharge amount shown in FIG. 16 in a predetermined period (in this embodiment, two weeks, hereinafter referred to as a request period). . For example, the request period No. 1 is a total of the required unloading capacity for two weeks for the elapsed days 1 to 14 in FIG. 2 is the total of the required unloading capacity for two weeks for the elapsed days 15 to 28 in FIG. The required unloading capacity within the request period is also called the request limit. The request period is not limited to two weeks, and may be any period such as one week.

[Provisional voyage pattern creation process]
The provisional voyage pattern creation unit 13 creates a provisional voyage pattern based on the calculation result (request frame) of the required unloading amount calculation process. FIG. 18 is information showing a list of route patterns, and lists all possible route patterns that define possible loading times, ship sizes, loading points, and landing points. Information relating to the ship size, hatch size, and number of hatches in FIG. 18 is based on the information shown in FIG. Note that the route patterns that cannot be taken due to restrictions are not listed in FIG. For example, as shown in FIG. 6, since there are loading and unloading sites where cargo handling work cannot be performed depending on the size of the ship, combinations that do not satisfy the restrictions due to the ship size are not listed as route patterns. In the present embodiment, the maximum number of loading places in a certain route pattern is a total of two places of the first loading place and the second loading place, and the maximum number of landing places is the first landing place and the second landing place. Although the case where there are two places in total will be described, the maximum number of loading points and landings is not limited to two, and may be three or more.

  The provisional voyage pattern creation unit 13 determines the loading brand and loading amount at each loading place of the route pattern and the loading brand and loading quantity at each landing place by solving the optimization problem shown below. Create a nautical pattern. First, the temporary voyage pattern to be created must satisfy the required frame. The relational expression between the unloading amount of each route pattern and the satisfaction of the required frame is expressed by the following formula (2-1).

  In addition, the temporary voyage pattern to be created will make the ship's cargo full. The constraint equation is expressed by the following equation (2-2).

  In addition, the constraint equations that loading and unloading are impossible at loading and unloading sites where ships do not call are expressed by the following equations (2-2) and (2-4).

ここでMB(r)及びPB(r)は、それぞれ以下を意味し、本明細書において以下同様の意味で使用される。
MB(r)：航路パターンrで寄港する積地で積載可能な銘柄mの集合
PB(r)：航路パターンrで寄港する揚地pの集合

Here, MB (r) and PB (r) mean the following, respectively, and are used in the same sense in the present specification.
MB (r): A set of brands m that can be loaded at the loading place that calls at port pattern r
PB (r): Set of landing sites p calling at route pattern r

  Further, the upper limit of the total amount that can be loaded for each brand is the loadable amount shown in FIG. Such a constraint equation is expressed by the following equation (2-5).

In the temporary voyage pattern creation process, optimization is performed so as to minimize the sum of absolute values of values representing excess and deficiency from the request frame. This objective function is expressed by the following equation (2-6).

  The provisional voyage pattern creation unit 13 sets each route pattern No. based on the above formulas (2-1) to (2-6). 1-No. For each of N, the loading amount and the unloading amount are determined. 1-No. N is created. FIG. 19 shows an example of a temporary voyage pattern. Each unloading amount represents the unloading amount at the landing site, and in order to unload the unloading amount, the same amount is loaded at the loading site. For example, tentative voyage pattern 1 in FIG. 19 is a tentative voyage pattern based on the route of route pattern 1. For brand I, 40,000 tons are loaded at loading site 4, and 40,000 tons are unloaded at landing site 4. It is carried out. Similarly, for the brand K, 100 thousand tons are loaded at the loading place 4 and 100 thousand tons are loaded at the landing place 4. Similarly, for brand F, 20 thousand tons are loaded at loading site 2 and 20 thousand tons are discharged at landing site 4. As a result of calculation, when the total amount of unloading is zero, it means that the voyage by the route pattern is not performed.

[Navigation pattern creation / selection process]
In the temporary voyage pattern shown in FIG. 19, the ship to be used and the voyage schedule in each request period are not fixed. In the tentative voyage pattern, although the landing site is fixed, it is not determined at which berth of the landing site the cargo handling operation will be performed. The voyage pattern creation / selection unit 14 is a process for determining these, and for each provisional voyage pattern, creates a plurality of voyage patterns by combining possible use vessels, voyage schedules, and cargo handling berths. FIG. 20 is information indicating an example of a plurality of voyage patterns created based on the provisional voyage pattern 2 of FIG. Each schedule of voyage patterns is calculated as follows.
Arrival date of loading area = departure date of Japan + (number of days of navigation between Japan and loading area)
Departure date = Departure arrival date + (Number of loading days at the first loading area + Number of voyages between the first loading area and the second loading area + Number of loading days at the second loading area)
First landing arrival date = loading departure date + (number of days between loading and landing)
1st landing site loading date = 1st landing site arrival date + 1st landing site arrival date 1st landing site loading end date = 1st landing site loading start date + 1st landing site loading day 2nd landing site Arrival date = End date of loading and unloading of the first landing site + Days of voyage between the first and second landing sites Second loading and unloading start date = Arrival date of the second landing site + Days of berthing at the second landing site End date of second landing unloading = Start date of second landing unloading + Number of second landing unloading days Here, the number of unloading days at the landing is calculated from the unloading efficiency information shown in FIG. 5 and the quantity to be unloaded. In addition, the voyage pattern of the schedule including the day when the ship cannot berth on the berth (the unacceptable day in FIG. 5) during the period from the start date of unloading and unloading is not created.

The dredger cost is set as follows.
Dredger cost of dedicated ship = 0
Spot dredger cost = (number of days from the departure date in Japan to the end of loading and unloading at the second landing) x cost (yen / day)
The above cost is based on the chartering cost for each ship size shown in FIG.

In addition, the following excess / shortage time is calculated when calculating the berthing fee / early departure fee.
Excess / shortage time (hr) = number of days of cargo handling at landing site-amount of cargo handling at landing site (t) / unloading run per ship (t / hr)
Here, the frying run for each ship indicates the set value (contract value) of the cargo handling efficiency for each landing place and each ship. If an efficiency exceeding the cargo handling efficiency set based on the contract can be achieved, the excess / deficiency time becomes positive and reward is obtained. If the efficiency falls below the set cargo handling efficiency, the excess / deficiency time becomes negative and a penalty occurs.
If the excess / shortage time is positive (when cargo handling ends earlier than planned), the early delivery fee is calculated based on the DES rate as follows. On the other hand, if the excess / shortage time is negative (when cargo handling ends later than planned), the berthing fee is calculated as follows based on the DEM rate.
Boat embarkation fee / early departure fee = DES (early departure fee) rate (yen / hr) x excess / deficiency time Boat embarkation fee / early departure fee = DEM (boat arrival fee) rate (yen / hr) x excess / deficiency time

  For example, voyage pattern No. i in Fig. 20 has the departure date in Japan as the planned start date, the first unloading berth as B2-1, the second unloading berth as B3-1, and the first and second landings. This is a voyage pattern that employs a combination of zero days for both lands. Navigation patterns No.i + 1 and No.i + 2 are patterns in which the number of days of stagnation at the second landing site is changed from the navigation pattern No.i. The voyage pattern No. j is a pattern obtained by changing the second landing landing berth from the voyage pattern No. i. The voyage pattern No. k is a pattern obtained by changing the departure date in Japan from the voyage pattern No. i. Sailing pattern No.l is a pattern in which the ship used is changed from a spot to a specific dedicated ship. Here, when considering a combination in which the departure date in Japan is changed, the first landing unloading start date is set within the request period of the original temporary voyage pattern. In addition, an upper limit is set for the number of days of berthing. The upper limit value is, for example, 10 days, and the voyage pattern for the number of days of berthing exceeding 10 days is not created. Based on the upper and lower limits of inventory transition, berth resource constraints, and various brand contract volume upper limits, solve the optimization problem using the objective function described later and select the voyage pattern to be used in the ship allocation plan . This optimization problem is expressed by the following mathematical formula.

  First, at a berth at a landing site, only one ship can unload, and other ships cannot simultaneously perform cargo handling work at the same berth. The constraint equation related to such a berth resource is expressed by the following equation (3-1).

  Also, when using a dedicated ship, the dedicated ship must not be engaged in another voyage at the same time. If a dedicated ship is used in another voyage, the dedicated ship cannot be used in the voyage pattern of the ship assignment plan. Such restrictions are expressed by the following mathematical formula (3-2).

  The inventory transition of each landing site is expressed by the following formulas (3-3) and (3-4).

  The constraint equation for the storage capacity at each landing site is expressed by the following equation (3-5).

  The upper and lower limits of inventory transition are expressed by the following formulas (3-6) and (3-7).

  The load capacity limit is expressed by the following formula (3-8).

ここでVは航海パターンvの集合を意味し、本明細書において以下同様の意味で使用される。

Here, V means a set of voyage patterns v, and is used in the same sense hereinafter.

  In the voyage pattern creation / selection process according to the present embodiment, a solution that minimizes the excess and deficiency from the upper and lower limits of inventory transition and the weighted linear sum of the transportation costs (the stagnation fee / early departure fee and the dredger fee). Ask. This objective function is expressed by the following mathematical formula (3-9).

  The voyage pattern creation / selection unit 14 performs optimization calculation based on Equation (3-1) to Equation (3-9), and selects a voyage pattern. A set of voyage patterns selected in this way becomes a ship allocation plan. FIG. 21 shows an example of a ship allocation plan describing the selected voyage pattern. The black line in FIG. 21 represents the period during which the ship is handling at the berth, the thin line is waiting for arrival at the berth, and the broken line represents the movement between the landings. Schedules can be made so that each other does not suffer from cargo handling, and when the berth is unusable (unloading is impossible), cargo handling is not carried out. Furthermore, as shown in FIG. 21, it can be seen that a ship allocation schedule taking into account multi-port loading and multi-port lifting has been created.

  As described above, according to the ship allocation plan creating apparatus 1 according to the first embodiment, when planning a schedule for transporting a plurality of brands of raw materials from a plurality of loading places to a plurality of landing sites, first, by ship. Calculate the required unloading capacity without considering transport restrictions. Then, a temporary voyage pattern is created from all the route patterns based on the necessary unloading amount, and a plurality of voyage patterns are created by determining a ship and a voyage schedule to be used in the temporary voyage pattern. From the voyage pattern created in this way, an optimization calculation is performed in consideration of the excess and deficiency from the upper and lower limits of the inventory transition and the transportation cost, and the voyage pattern is selected to create a shipping plan. Therefore, it is possible to create a ship allocation plan that takes into account both the stable supply of raw materials to a plurality of landing sites and the minimization of transportation costs without performing a simulation.

  In the present embodiment, the above optimization calculation is solved by the mixed integer programming, but the present invention is not limited to this. For example, optimization problems can be solved by optimization methods such as mixed integer programming, constraint programming, and metaheuristics.

(Embodiment 2)
The second embodiment of the present invention will be described below. The ship allocation plan creating apparatus 1 according to the second embodiment is different from the configuration according to the first embodiment in that a type list in which brands that can be substituted between brands is used is used. Since each component is the same as the configuration according to the first embodiment, description thereof is omitted.

  If there is something that can be replaced between brands, inventory transition may be considered in the type unit that aggregates brands, not in brand units. FIG. 22 shows classifications of brands. In addition to the information shown in the first embodiment, the data reading unit 11 of the ship allocation plan creating apparatus 1 according to the second embodiment reads the type list. In the second embodiment, in each process, a value obtained by summing up information on initial stock and consumption in units of types instead of units of brands is used, and some formulas for optimization problems in each process are changed to units of types. Use. In the following description, it is assumed that a set of type g is G, and MG (g) represents a set of issues m belonging to type g. First, formulas (1-1) to (1-8) of the optimization problem of the required unloading amount calculation process are changed as follows.

  In addition, among the formulas for the optimization problem of the provisional voyage pattern creation process, Formula (2-1) and Formula (2-6) are respectively changed as follows.

  In addition, among the formulas for the optimization problem of the voyage pattern creation / selection process, the formulas (3-3) to (3-9) are changed as follows.

  In the second embodiment, the navigation pattern is selected by performing optimization calculation using the above-described changed formula. The set of selected voyage patterns is the ship allocation plan. Similarly to the first embodiment, the ship allocation plan creating apparatus 1 according to the second embodiment also performs a ship allocation plan that takes into account both the stable supply of raw materials to a plurality of landing sites and the minimization of transportation costs. It is possible to create. In addition, when there are raw materials that can be substituted between brands, it is possible to create an optimum ship allocation plan that takes into account substitution between brands by calculating by type.

(Embodiment 3)
In the above embodiment, when creating a voyage pattern in the voyage pattern creation / selection process, consideration is given to the case where either a spot ship or a dedicated ship is used. However, as the number of dedicated ships increases, the number of voyage patterns increases explosively, which increases the calculation load of optimization calculation in the voyage pattern creation / selection process and may increase the processing time. Therefore, in the voyage pattern creation / selection process voyage pattern creation, the voyage pattern is created as a spot ship without considering the use of a dedicated ship. A dedicated ship is assigned in the selected voyage pattern.

  FIG. 23 is a block diagram of a ship allocation plan creation device 1c according to the third embodiment of the present invention. The ship allocation plan creation device 1c according to the third embodiment is different from the configuration according to the first embodiment in that an allocation processing unit 15 is provided. In addition, since each component is the same as the structure which concerns on Embodiment 1, it attaches | subjects the same code | symbol and abbreviate | omits description.

  FIG. 24 is a flowchart showing an outline of the operation of the ship allocation plan creating apparatus 1 according to the third embodiment of the present invention. Steps S100 to S300 are the same as those in the first embodiment, and a description thereof will be omitted. As a rough outline, in the voyage pattern creation / selection process, the voyage plan creation device 1 according to the third embodiment creates a voyage pattern assuming that all the ships used are spot ships in the voyage pattern creation / selection unit 14 (step S400c). Subsequently, the allocation processing unit 15 allocates a dedicated ship to the selected voyage pattern (step S500). In this way, a navigation pattern (also referred to as a ship allocation navigation pattern) in which spot ships or dedicated ships are allocated is used in the ship allocation plan. Hereinafter, the allocation process will be described.

[Dedicated ship assignment process]
The allocation processing unit 15 creates a combination of the selected voyage pattern, dedicated ship, and spot ship based on the voyage pattern in the voyage pattern creation / selection process. FIG. 25 shows the selected nautical pattern, dedicated ship, and spot ship combination. The optimal combination is selected from the combination. The optimization problem is expressed by the following mathematical formula.

  First, one ship allocation voyage pattern needs to be selected for each selected voyage pattern. This restriction is expressed by the following equation (4-1).

  Next, it is necessary that the dedicated ship is not engaged in another voyage at the same time. Such restrictions are expressed by the following formula (4-2).

  In the dedicated ship allocation process, the objective function is the minimization of dredger cost and berthing / early departure fee, and is expressed by the following equation (4-3).

  The allocation processing unit 15 performs an optimization calculation based on the above formulas (4-1) to (4-3), and selects a ship allocation voyage pattern. A set of ship allocation voyage patterns selected in this way becomes a ship allocation plan.

  Similarly to the first and second embodiments, the ship allocation plan creating apparatus 1 according to the third embodiment also considers both the stable supply of raw materials to a plurality of landing sites and the minimization of transportation costs without performing a simulation. It is possible to create a ship allocation plan. In addition, the use of a dedicated ship is not considered in the creation of a navigation pattern in the navigation pattern creation / selection process, but a navigation pattern is created for all spot ships, and a process for assigning a dedicated ship in the selected navigation pattern is separately performed. Thereby, even when the number of dedicated ships increases, the time required for calculation processing can be suppressed.

  Here, a computer can be used in order to function as the ship assignment plan creation device 1 and the ship assignment plan creation device 1c, and such a computer performs processing contents for realizing each function of the ship assignment plan creation device 1. The described program can be realized by storing the program in a storage unit of the computer and reading and executing the program by a central processing unit (CPU) of the computer.

  Although the present invention has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention. For example, the functions included in each means, each step, etc. can be rearranged so that there is no logical contradiction, and a plurality of means, steps, etc. can be combined or divided into one. .

DESCRIPTION OF SYMBOLS 1, 1c Ship allocation plan preparation apparatus 10 Database 11 Data reading part 12 Required unloading amount calculation part 13 Temporary voyage pattern creation part 14 Navigation pattern creation and selection part 15 Allocation processing part

Claims (7)

A ship allocation plan creation method for creating a schedule for transporting a plurality of brands of raw materials from a plurality of loading sites to a plurality of landing sites,
Raw material information including the stock amount and stock upper and lower limit values of each raw material for each landing site, landing information including the loading efficiency regarding the berth for each landing site, loading site including the amount of loadable raw material for each loading site A data reading step for reading information relating to a ship allocation plan having ship information including information, ship capacity to be used and transportation cost;
A required unloading amount calculating step for calculating an unloading time at each landing site and an unloading amount for each unloading based on the upper and lower limits of the stock without considering restrictions on transportation by ship,
Temporary voyage pattern creation that creates a temporary voyage pattern that defines the loading material and loading amount at each loading point of the route pattern and the loading material and loading amount at each landing point, based on the calculation result of the necessary loading amount calculation step Steps,
A plurality of voyage patterns are created based on the tentative voyage pattern, and a voyage pattern for selecting a voyage pattern to be used in a ship allocation plan based on excess and deficiency from the inventory upper and lower limit values and transportation cost from among the created plurality of voyage patterns Creation and selection steps;
How to create a ship allocation plan including In the data reading step, a type list in which brands that can be replaced between brands among the plurality of brands is aggregated is read,
In the required unloading amount calculation step, the unloading time at the landing site and the unloading amount for each unloading are calculated for each type,
In the provisional voyage pattern creation step, the provisional voyage pattern is created by determining the loading material and the unloading material for each type,
2. The ship allocation plan creation method according to claim 1, wherein, in the voyage pattern creation / selection step, a voyage pattern is selected based on a stock upper and lower limit value for each type.   The voyage pattern creation / selection step includes an assignment process of selecting a voyage pattern without considering the use of a dedicated ship and assigning the dedicated ship to the selected voyage pattern. How to make a ship allocation plan.   The operation method of operating using the ship allocation plan created by the ship allocation plan creation method as described in any one of Claims 1 thru | or 3. A ship allocation plan creation device for creating a schedule for transporting a plurality of brands of raw materials from a plurality of loading sites to a plurality of landing sites,
Raw material information including the stock amount and stock upper and lower limit values of each raw material for each landing site, landing information including the loading efficiency regarding the berth for each landing site, loading site including the amount of loadable raw material for each loading site A data reading unit for reading information relating to ship planning including ship information including information, ship capabilities to be used and transportation costs;
Without considering the restrictions on transportation by ship, based on the upper and lower limits of inventory, a required discharge amount calculation unit that calculates the discharge timing at each landing site and the discharge amount for each discharge,
Temporary voyage pattern creation that creates a temporary voyage pattern that defines the loading material and loading amount at each loading point of the route pattern and the loading material and loading amount at each landing point based on the calculation result of the required loading amount calculation unit And
A plurality of voyage patterns are created based on the tentative voyage pattern, and a voyage pattern for selecting a voyage pattern to be used in a ship allocation plan based on excess and deficiency from the inventory upper and lower limit values and transportation cost from among the created plurality of voyage patterns Creation / selection section,
A ship allocation plan creation device. The data reading unit reads a type list in which stocks that can be replaced among stocks among the stocks are aggregated,
The required unloading amount calculation unit calculates the unloading time at the landing site and the unloading amount for each unloading for each type,
The tentative voyage pattern creation unit creates a tentative voyage pattern by determining the loading material and the unloading material for each type,
6. The ship allocation plan creation device according to claim 5, wherein the voyage pattern creation / selection unit selects a voyage pattern based on a stock upper and lower limit value for each type. The voyage pattern creation / selection unit selects a voyage pattern without considering using a dedicated ship,
The ship allocation plan creation device according to claim 5 or 6, further comprising an allocation unit that allocates a dedicated ship to the selected voyage pattern.

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