ProSched^® is a plant scheduling software that includes three modules for feedstock scheduling, product scheduling and operations scheduling. The feedstock-schedule module facilitates quick scheduling of receipts, tank farm and blending. ProSched^® has the flexibility of taking input from any production planning software via macros and the Microsoft Excel interface. The feedstock-scheduling module allows the user to schedule operations that extend from the time the feedstock arrives at the loading area till the blended feed is ready to go to unit operations.

The Ingenious Group has developed this state-of-the-art scheduling product. Our group has rich experience in the fields of planning, scheduling, process simulation and engineering. Along with its affiliates and partners in North America and Asia , the Ingenious Group has been marketing and providing implementation services for the popular production planning software: PetroPlan^®. Additionally, Ingenious has been involved in providing basic engineering and process simulation services. Ingenious has collaborated with RSI, France , a subsidiary of IFP to develop this state-of-the-art scheduling tool using their INDISS simulation platform.

The overview graphic (Figure 1) indicates the schematic of the entire process and provides links to the detail, schedule, summary and Gantt charts for each area of the process such as tanker, tank, berth, and blender. Depending on the complexity of the facility the schematic can be customized. 

ProSched^® feedstock scheduling module facilitates the following scheduling functions:

·         Day-to-day feedstock scheduling activities

·         Feedstock receipts

·         Tank loading, lineups and transfers

·         Oil movement & storage

·         Blenders/blend tanks lineups and recipes

·         Inventory management

·         Default and custom constraints

• State-of-the-art simulation engine for evaluating feasible schedules and optimization
• Convenient and user-friendly data entry
• Modern graphical user interface (GUI) with a user-friendly method for viewing data.
• Integral, dynamic and intuitive report generation.
• Reports, schedule and Gantt charts available for individual unit operations such as berth, tank, etc.
• Complete data access and user-friendly operation
• Easy troubleshooting and modification of scheduling operations
• Quick solution and schedule optimization
• Plan Vs Actual evaluation with multiple case comparison
• Input from production planning package for Feedstock blend and recipes.
• Integrated exporting tools for exporting schedule to third party packages.

The user can enter data automatically via built-in macros as well as manually.  ProSched^® has a dynamic interface with Microsoft Excel that allows the user to have data input from third party databases and interfaces. (Figure 2) This data is entered before the schedule is generated in ProSched^®. User also has the option of manually altering that data. On the same lines, data and reports can be easily exported from ProSched^® to other third party databases including Excel via ODBC exchange.

Figure 2: ProSched data entry form

ProSched^® is designed to produce schedules that can be realistically implemented in the plant. This implies schedules that meet all physical and operational constraints and also maximize material run lengths on the blenders, process units and tank movements. Operational constraints include, amongst others, such things as Minimum/maximum tank inventories (heels), Minimum and maximum inventory levels of components and products, Minimum blender run lengths, Time requirements for blender setup, tank line-up, and testing.

Often it is not possible to meet all these requirements simultaneously. In this event the system will successively relax constraints, in a user-defined order, until a schedule is achieved. The last constraints to be relaxed are tank heel and capacity limits. A schedule that requires the relaxation of heel or capacity limits is referred to as an infeasible schedule. A typical 720-hour (One month) schedule is generated as shown in Figure 3. Detailed schedule for each operation is generated and the user can scroll down to get information from hour 0 to hour 720. This information is further used to generate the Gantt charts and overall schedule report.

The modeling code is developed using Microsoft Visual C++, which is integral to the simulation engine. There are built-in algorithms, which contain certain predetermined rules and infeasibilities, so if the user tries to choose an infeasible production run, a window will pop up indicating the error.

Figure 3: 720 hour berth schedule

A schedule is optimized based on the algorithms, rules, and constraints in the model including factors such as demurization costs, tanker availability, berth capacity, tank capacity, type of feedstock, etc. A summary report is generated for each operation, as shown in Figure 4, indicating key variables such as inventory, capacity, output/input rate, description, service etc.

Based on the algorithms the most optimized solution is obtained in a schedule run. If the desired schedule is infeasible an error message will indicate the source of the infeasibility. This allows the user to modify the constraints, revise the schedule and obtain a feasible solution.

Schedules can change during a certain period depending on changes in certain variables in the real plant. This can be reflected in ProSched^® by altering the changed variable in the model and running the schedule again. The user can easily change the schedule period from 1day to 1 week to 1 month (720 hours).

Figure 4: Tank summary

Based on the information entered by the user, ProSched^® determines the properties of each operation such as schedule time, cargo code/name, arrival time, supplier, amount and other specific properties (Figure 5).

Figure 5: Details of Tanker unit

ProSched^® graphically displays the final feasible schedule, which can be modified by user for further upsets during scheduling period. Production run is determined by its start date and time, end date and time, time runs and throughput. User can modify production runs; properties of selected run and any changes will be instantly updated on the Gantt chart.

 

Figure 6: Overall Process Gantt chart

ProSched^® allows the user to compare several schedule runs and also make a direct comparison between the schedule suggested by the production planning package and the actual schedule generated for that period based on realistic constraints and physical limitations of the plant. There are several reasons why the actual schedule could be different from the planned one. Some of the factors that contribute to the disparity include tanker arrival/departure times, unavailability of the desired feedstock, capacity limitations of tanks, pumping rate limitations, failure of certain pieces of equipment, unavoidable delays in certain actions etc. The ideal situation entails a perfect match between the planned and actual schedule. However that seldom occurs in the plant. Based on the realistic scenario, the schedule generated can be transmitted to the production-planning package to alter the plan based on the realistic scenario. This calls for good plan vs. actual calculations as well as integration between the planning and scheduling software.

Ingenious Group has the qualified staff to help customize the scheduling operation for your plant using ProSched^®. We also have offices located in North America and India to help support projects in different regions of the world. We request you to contact us if there are more questions or queries regarding ProSched^® and our other planning and simulation services.