Central Supply Logistics System
Recently implemented at Jarí Celulose, the Central Supply Logistics System indicated a potential reduction in 60% of wood movement at the Munguba Yard, amongst other direct and indirect gains.
Jarí processes, with its cellulose and energy plants, 4.300 t and 1.000 t of wood per day, respectively. The plants are located at Vila Munguba, in Monte Dourado (PA), and are supplied with eucalyptus transported by road or rail transport. The private rail network connects the Munguba yard to three intermediate yards (São Miguel, Pacanari and Ponte Maria) which are supplied with wood from the fields by subcontracted trucks. The wood which is directly delivered by truck to Munguba is from Amapá (by crossing the Jari river) and surroundings.
The Munguba Yard possesses a number of railway lines for parking a mix of wagons loaded with wood or awaiting to be transferred back to the intermediate yards. Each of these lines possesses a certain extension, which limits the quantity of wagons that can remain parked (and consequently the quantity of wood in stock). Besides this, some lines are specialized according to the type of wood which may be stored, due to restrictions or operational convenience. The LPM, for example, is a line which supplies the wood peeling machine: therefore, it only stocks wood with bark.
It is common practice to avoid unloading wood wagons on the floor, since internal movements generate additional costs. In certain critical situations, this movement is justified due to necessity in freeing wagons.
Integration between the harvesting and transport system’s several agents (yards, trucks, trains and plant) is done through Alfa, a radio communication’s system managed by the Forestry Operations Management at Monte Dourado. Besides linking communications between several areas, Alfa consolidates information regarding the movements in the several yards (inputted through palmtops) and wood consumption at the plants.
The proper operation of a harvesting and transport system requires agile, integrated and optimized decision making. It must be guided, obviously, by the demand from the energy and wood chip production lines. However, the wood cutting schedule is guided by costs and operational constraints due to the process itself, which end up limiting the wood availability for the plants. The effective management of the stock policy of each type of wood at the various yards is a necessary condition for the correct supply of demand, according to a controlled movement cost. Furthermore, it is necessary to have a rational and optimized use of transport resources in the system: locomotives, wagons, loaders and trucks.
Alfa enables integrated decision making. It also allows for a quick response to variability’s within the process, such as, for example, unscheduled interruptions at the lines, late arrivals of loads, etc. However, the system’s complexity, through the various alternatives of each decision (expanded by the logical consequences of these various decisions), require the use of analytical and computational tools, without which the generation of optimized and agile plans (and even more, feasible from an operational point of view) is an extremely difficult task. At the beginning of 2009, Jarí Celulose hired UniSoma to develop a Central Supply Logistics System, which could support the supply planning for the energy and cellulose production lines. This solution should be able to deal with a set of interrelated plant supply decisions, such as:
- When and to which yards should the locomotives/wagons available at Munguba be sent to?
- With which type of wood should eht locomotives/wagons available at the intermediate yards be load with and when will they be available to return to the plant?
- Once at the plant, to which production line should each full locomotive/wagons be sent to?
- Should the wood wait to be used in the wagon or laid on the ground? The strong operational bias of the supply problem imposed additional project requirements, if compared to problems of a tactical or strategically type. The system should be agile to update information and provide an optimized solution quickly. Besides this, it was fundamental that the system handle input data inconsistencies preventing that, under no circumstances, the system return an infeasible solution due to numerical issues.
The main component of the System is the Programming Module (Optimizer), where the production lines supply plans are generated. This Module is synchronized with a corporate database, where the intermediate yard movements and other information (breakdowns, lines consumption, locomotive status) are capture and stores. The plans generated by the Optimizer are made available to the intermediate yard the operators through the same palmtops that are used to register movements.
The Optimizer was developed in AIMMS language. With a mathematical mode, it allows for the automatic generation of optimized and integrated plans. Furthermore, it uses an intuitive and graphically rich interface to facilitate the interaction of the planner-user with the mathematical model. The user friendly GUI and the feasible solution in reasonable time were critical to the project, given the operational nature of the problem. The system also has a management cockpit through a web interface developed in JAVA for remote and real time monitoring of business metrics and system use.
In use since August 2010, the system indicates a potential reducion in 60% of internal movements in Munguba, a result of the increase in direct unloading of wood to the production lines. Furthermore, greater stability in the supply of wood to the lines, with reduced interruptions as a result of unbalanced plans. Better use of storage and transport assets allow for a postponment of investments to increase logistical capacity decuring from an increase in plant capacity.
About Jarí Celulose
Jarí Celulose is located in Vila Munguba, at Monte Dourado (PA), close to the border of the State of Amapá and the margins of the Jarí river. Controlled by the Orsa Group since 2000, the company was part of the Jarí Project, a grand enterprise concieved by north american bilionare Daniel Keith Ludwig who, in the 60s, brought from Japan, through floating platforms, a cellulose plant and an energy production plant (55 MW). The cellulose plant is the only within its sector to have 100% FSC certification for the whole chain of custody, and concentrates its production in bleached eucalyptus kraft pulp (BEKP), mainly to supply the external market.