Bell Annealing Shop Scheduler - BASS™
Functional Specification Summary

Overview
The WSE Bell Annealing Shop Scheduler (BASS™) program is designed to maximize the throughput of a batch annealing facility. The program considers disposition of all equipment including bases, furnaces, cooling covers cranes etc. It also evaluates the properties of the available pool of stacks to be annealed. When combined with the Bell Annealing Stack Builder BASS™ will create the stacks from available coils.

BASS™ runs on a Microsoft Windows 95/NT platform and comes complete with a graphic user interface, known as the Bell Annealing Shop Manager (BASM™). BASS™ interfaces to existing level II process control systems to get the current operating state of the shop. In this way it is able to determine a shop schedule or plan for future equipment moves and charges in order to maintain a well balanced shop. A well balanced shop is defined as one with a minimum amount of idle or waiting time. Idle time occurs, for example, when a base is ready and waiting for a furnace but none are currently available. BASS™ comes standard with a single user InterBase RDBMS but can be configured to work with MS SQL, Oracle, Informix or Sybase. In planning shop equipment moves and charges, BASS™ takes many items into consideration. Many of these are outlined below.

Equipment Properties
Equipment consists of annealing bases, furnaces, cooling covers, cranes, and in some cases cooling stands and innercovers. BASS™ recognizes the following equipment properties:

Bases
B_ID - The unique identification number of the base.
B_LOC_X, B_LOC_Y - The physical location of the base in the annealing shop.
B_STK_COUNT - The number of stacks the base can handle (i.e. single stack, four stack).
B_STATE - The current state of the base. This includes the current operation (e.g. heating), the time that the operation started, and the predicted duration of the current operation.
B_SCHED - The planned schedule of operations for the base. This is built dynamically by BASS™.
B_MAINT_SCHED - The scheduled maintenance plan for the base. This is used by BASS™ to plan around known outages.

Furnaces
F_ID - The unique identification number of the furnace.
F_LOC_X, F_LOC_Y - The physical location of the furnace in the annealing shop.
F_STATE - The current state of the furnace. This includes the current operation (e.g. awaiting ignition), the time that the operation started, and the predicted duration of the current operation.
F_SCHED - The planned schedule of operations for the furnace. This is built dynamically by BASS™.
F_MAINT_SCHED - The scheduled maintenance plan for the furnace. This is used by BASS™ to plan around known outages.

Cooling Hoods
C_ID - The unique identification number of the hood.
C_LOC_X, C_LOC_Y - The physical location of the hood in the annealing shop.
C_STATE - The current state of the cooling hood. This includes the current operation (e.g. water spray cooling), the time that the operation started, and the predicted duration of the current operation.
C_SCHED - The planned schedule of operations for the hood. This is built dynamically by BASS™.
C_MAINT_SCHED - The scheduled maintenance plan for the cooling hood. This is used by BASS™ to plan around known outages.

Cranes
CR_ID - The unique identification number of the crane.
CR_LOC_X, CR_LOC_Y - The physical location of the crane in the annealing shop. This is used to determine which bases can be served by the crane. BASS™ will not schedule two or more cranes to perform an operation which would be impossible to perform given the layout of the shop. Since most shops employ overhead cranes on a common set of rails, it is obviously impossible for the cranes to crossover. In addition, there are safety restrictions to be considered when two or more cranes are working in the same area of the shop.
CR_STATE - The current state of the crane. This includes the current operation (e.g. packing a base with coils), the time that the operation started, and the predicted duration of the current operation.
CR_SCHED - The planned schedule of operations for the crane. This is built dynamically by BASS™.
CR_MAINT_SCHED - The scheduled maintenance plan for the crane. This is used by BASS™ to plan around known outages.

Stack Properties
Stacks built by BASB™ or manually have the following properties:
S_NUM - Unique identifier for the created stack.
S_WGT - Net weight of the stack not including base, separator or convector plates.
S_H - Total height of the stack including base, separator or convector plates.
S_DD - Latest date that the stack must be finished annealing and ready for any follow on processing.
S_DI - Date the stack was placed in inventory, equal to the least recent C_DI in the stack.
S_Q - Quality of the stack, equivalent to the highest C_Q in the stack.
S_P1 and S_P2 - Priority level 1 and 2 equal to the highest C_P1 and C_P2 in the stack.
S_ODD - The cumulative outside diameter difference of all coils in the stack.
S_HTD - The cumulative heating time difference of all coils in the stack based upon the C_ANT property of each coil in the stack.
S_HM_AT2 - Predicted anneal time for the stack based upon empirical data accumulated over time by BASB™.
S_HM_AT3 - Refined predicted anneal time for the stack based upon a customer supplied heating model.

Shop Scheduling Algorithm Considerations
In general, BASS™ will attempt to plan the shop schedule of operations and charges in order to minimize the amount of waiting/idle time in the shop. It does this by first looking at the state of all equipment in the shop, typically by interfacing to an existing level II SCADA system. It then looks at the future availability of equipment and stacks awaiting annealing and schedules equipment moves and charges in order to minimize the idle or waiting time for a base. In doing this, BASS™ also considers the properties for stacks awaiting annealing such as delivery time. When the Bell Annealing Stack Builder (BASB™) component is included, BASS™ will be given several stack variations from which to choose when planning the shop schedule. Tuning parameters are available to control the behavior of BASS™. For example, it is possible to force BASS™ to maximize shop throughput in spite of the delivery deadlines placed on individual coils.

Shop Planning with BASS™
BASS™ can also be used to play out "what if" scenarios. For example, a shop planner, knowing he needs to do routine maintenance on a furnace, can enter the maintenance operation and then see what impact this would have on his shop's balance. In the case of a severe impact, he might decide to wait until the following day at which point he could try test it again. Similar "what if" trials can be run for maintenance of any item, for seeing what would happen if a crane was diverted to another area of the mill, or to see the effect of changing priority or delivery for a given set of coils, perhaps to satisfy a customer request.

The planner can override BASS™ in order to force a given stack to be the next one charged or to specify a particular base to be used for a charge. Again, he can use "what if" trials to determine the impact such a move would have on his shop balance and throughput.

Reporting and Analysis
BASS™ includes several standard reports for viewing and analyzing shop scheduling and stack data. BASS™ accumulates a history of schedules and events for a shop, allowing the planner to replay events which have taken place in an attempt to isolate reasons for low productivity. Because all information is maintained in an open architecture, relational database, data analysis with BASS™ is limited only by the imagination of the user. BASS™ can export coil, stack, equipment, maintenance and schedule data into a tab or space delimited ASCII file which can then be imported into popular spreadsheet programs like Lotus, Excel and Quattro Pro. In addition, ODBC can be used to access the BASS™ database from other SQL compliant programs and tools.

For more information, follow one of the hyperlinks below.

Download Complete BASS™/BASB™/BASM™/BACT™ Specification PDF file (700 KB)

Overview of the BASS™ Component Topology

BASS™ System Data Flow Diagram

BASB™ Functional Specification Summary

BASB™ Sample Screen Captures