Rootstock Material Requirements Planning (MRP) is the software engine that will use the sales order and forecast demands in conjunction with the effective production bill of material and by reviewing item inventory balances will generate planned supplies in a time-phased manner to offset the outstanding demands for end items and sub assemblies.
Specifically, MRP generates what are termed planned work orders for manufactured items and planned purchase requisitions for purchase or subcontract items. For firmed (or greater supplies) it generates reschedule or excess messages when, and if, appropriate.
Rootstock Material Requirements Planning (MRP) uses information from Sales Order Management to drive the top level demands. Forecast demands, or not only end items but any item can be entered as well. A forecast demand for an item denotes the start period date and the end period date and the quantity forecasted for that period. MRP will perform the traditional ‘netting’ and plan to the greater of the Sales Order Demand and Forecast demand (by period).
The MRP Engine uses the typical algorithms in the industry and will proceed level by level through the Bill of Material starting with the top level (i.e. end item) of the BOM and review the demands and safety stock requirements, netting out the inventory and firmed (or greater) supplies and first suggest reschedules for firmed (or greater) supplies and then create planned supplies as appropriate.
The MRP Engine will always use the ‘effective’ Bill of Material in its plan. It accomplishes this by reviewing the scheduled pick dates of the planned work order supplies or planned subcontract requisition supplies and using that date to extract the components that are ‘effective’ and ‘implemented’ as of that date in the generation of the work order and subcontract requisition demands.
MRP can be planned by division and by site as well as by project (in those divisions where project control is applicable). It uses planning policies such as ‘lot for lot’ or days cover. Since many lead times can be stipulated at the item (or commodity code) level, the MRP Engine also determines for the work order supply the scheduled firm date, scheduled release date, scheduled pick date as well as the scheduled start date on the shop floor and the scheduled due date. For a requisition, it will determine the scheduled firm date, purchase order place date, date it is due on the receiving dock as well as the due date it is to be stocked. For those parts identified as items to be planned using ‘re-order’ point, the MRP Engine can also perform re-order point computations.
Rootstock Scheduling & Capacity Planning provides the management and monitoring of the work order operations’ scheduled dates that are required to meet the Material Requirements Planning Work Order’s Scheduled Due Date into Stock.
The Rootstock Scheduler develops a schedule for all firmed, release and ‘in process’ work orders based on the due date, standard times extended by the work order quantity, priority (as derived from compressed float), move and queue times and the work center’s standard for the hours in a production day.
The Capacity Requirements Planning will allow one to view a work center’s available capacity on a day by day basis (in terms of labor hours or machine hours) in a colorful graphical format. The ‘drag and drop’ feature supports moving the schedule for a given work order within a work center from one day to another. If moving up the priority (and display) of a work order within a work center is required, this ‘drag and drop’ feature allows the altering of the priority. The schedule is adjusted automatically when the ‘work order’ is moved from one day to another.
The work order scheduling logic is performed for each work order, in a stepped method, establishing certain criteria at the end of each step before ultimately determining each work order operation’s scheduled start date and scheduled complete date. The determination of the operation standard time is influenced by a number of factors.
The first step in the scheduling algorithm is to establish the first work order’s operation’s schedule start date. If the work order has as not yet been started and the Work Order Production Release Dates is later than today’s date, then first operation’s schedule start date is the Work Order Production Release Date. If the Work Order Production Release Date is less than (or equal to) today’s date, then the first work order’s operation schedule start date is set to today’s date. If the work order has been started, then the first work order operation’s scheduled start date, not as yet completed, will be set to today’s date.
The next step is to determine the subsequent work order operations’ scheduled start and scheduled complete dates. This is accomplished by computing the scheduled quantity at the operation and then using that quantity in conjunction with labor and machine standards to determine the expected time to be expended in a work center for this operation. Considering the length of the standard production day will determine if this expended time (assuming infinite capacity) can be completed on the current scheduled date or a later date. The algorithm, when establishing dates for the next operation, will use the scheduled complete date of this operation that was previously scheduled and then add move and queue times to determine the present operation’s scheduled start date. The quantity to be scheduled will be adjusted based upon actual or expected scrap of the prior operation.
Given that this is a forward scheduling method, the next step in the process will determine the priority using a comparison between the standard (or natural) move and queue time and the compressed move and queue time required to meet the Work Order Scheduled Due Date into Stock. If a compression can be done, then the work order operations’ scheduled start and scheduled complete dates will be readjusted to meet the Material Requirements Planning Work Order Scheduled Due Date.
The Capacity Planning Work Bench is launched from the Manufacturing Menu. In the capacity planning work bench, the user, using the easy to use ‘drag and drop’ capability, can move the ‘work order operation start date’ forward or backward and the scheduling algorithm described above will be executed.
The work order operation’s start date (and scheduled complete date) will determine which work center day slots the work order will occupy. The priority will determine the order of the listing within the work center. Those work orders in green are expected to be started within the ‘available capacity’ and those in red ‘exceed capacity’. It is expected that the user may change the position of the work order within a work center by altering the priority and for those work orders in red, it is expected that the user, via a ‘drag and drop’ capability, will move them to another day.
Rootstock Inventory Control supports a number of Manufacturing and Distribution business processes relating to the maintenance of item inventories, inventory valuation and planning and setting of item policies such as lead time and MRP or RP planning. Purchase Requisition Maintenance for Direct Material Items is also supported in this module as is a Supply Demand Review (an output of MRP or RP) which illustrates the supply and demand picture with projected on hand balances helpful to a material planner for managing the inventory.
While products, items, and production items are initially entered in the Product Management application or Production Engineering application, for those that are entered in an active status, the Rootstock Item Master maintenance function will automatically establish Inventory part policies and attributes such as lead times and MRP and RP planning polices and Safety Stock policies as determined by the Inventory Commodity code assigned during this item master maintenance.
It is important to understand the structure of the inventory information to appreciate all of the tracking of costs and quantities that are maintained. All inventories (quantities) are maintained by Item and Location within a Division and Site. The Location is a combination of both a Location ID (typically a physical location with a distribution center or plant such as Stores or Floor Stock) and a Location Number (typically a ‘row-bin-aisle’). The Location ID’s have their own master file and are identified as ‘on hand nettable’ or ‘on hand non nettable’ – and the Sales Order Management, MRP, or RP modules will only review and allocate inventory that is located in On Hand Nettable locations.
There are additional attributes ‘assigned’ to inventories and they are as follows:
In a project control environment, it is necessary to also maintain the inventories by project. Therefore, an additional piece of information on the Item Location Record is the project.
While the user will maintain the inventories at a Division, Site, Item, Project (if Project Control environment), Location ID, Location Number, Serial (if a Serial Controlled item), Lot (if a Lot Controlled item), Location Section (for Backflush locations), the system also has additional records containing the quantities (and dollars) by Division-Site-Item and by Division-Site-Item-Project (if Project Control environment).
There are a number of transactions that are available to the user to maintain inventories. Some of the inventory transactions available include:
In a moving average cost system, the user will need to note the unit costs on an inventory addition while in a standard cost system the costs are not on specified on the transaction by the user.
As noted earlier there is a Supply Demand Review (also termed Requirements Analysis) that is available for each item. This Requirements Analysis presents the supplies (work orders, purchase requisitions, purchase orders) and demands (customer orders and forecasts, work order demands, subcontract requisition and subcontract purchase order demands) in due date sequence with an associated projected on-hand balance. The planner can review this supply and demand picture on line and it is helpful in managing reschedules and review of shortage conditions. Purchase requisitions are also maintained through Inventory Control. The material planner can add requisitions within this module and then once the requisitions are approved they can be converted to Purchase Orders within this module. MRP generates planned requisitions. Planned requisitions must be changed to firm status prior to their being approved.
Another benefit provided by the Inventory Control module is the comprehensive Audit Trail Inquiry. An audit trail is generated for every material movement and labor transaction. The Audit Trail Inquiry can be used to track the historical view of an item’s increments and decrements to inventory or the cost associated with determining the inventory balance.
Device History Record
Rootstock Device History Records are created and maintained in a tree structure that links serialized components to Serialized parents, starting with a Serialized Item at the top level with links to Work Order Issues and PO Receipts. All transactions relating to the Device History are captured.
Rootstock Lot & Serial Control provides for an item’s lot or serial number to be registered through Purchasing Receipts, Inventory, Shop Floor Control and Sales Order Fulfillment functions.
The Purchasing Receipt function will note the Item Number classification and if ‘lot controlled’, then the lot number must be assigned to the entire Purchase Receipt for the items being received prior to their ‘acceptance’ into stock. There is an option that allows the user to assign the ‘receiver number’ as the lot number which provides for an easy but practical application for the lot identification.
If the Vendor assigned a lot number, then this can be assigned by the user instead. If the Item Number is ‘Serial Controlled’, then prior to the receipt into stock, the serial numbers can be assigned in a ‘free form’ text field. The software will parse that text box to insure that serial number records are created on the Purchase Receiver and on Item Location Records as well as an ‘item serial record’, insuring that only one serial can be assigned an item.
The lot or serial number, as required, is registered on all inventory additions, adjustments and scrap transactions. While Lot and Serial controlled items are not appropriate for ‘backflush’ considerations, all other inventory, work order and subcontract order issues record the lot or serial as required on the issue transaction.
On work order supplies the user must record the lot number for ‘lot controlled items’ and this recording must be done before the assembly is received into stock or scrapped. Likewise, serial numbers must be assigned before the work order assembly is received or scrapped.
Pick lists are printed with serial number detail and lot information as appropriate. When sales order is fulfilled the serial number of the final assembly is noted on shipment.
Before defining the Routing, the labor grades, departments, work centers, machine master files and processes must be defined by the manufacturing engineer (and cost accountant when denoting the labor grades and departmental standard labor and overhead rates). Those master files having been defined, a Routing can be established for each item.
The Routing will be comprised of a series of steps (i.e. operations). Each operation will denote the work center, machine (if appropriate), labor grade and process – and the time it takes to do a unit or a batch of work. These times can be a) setup, or b) labor assembly or c) machine time. An operation can also be identified as an ‘outside operation’ where the assembly is sent to a vendor for additional processing. For those organizations that want to control the operation’s effectivity date (e.g. the ability to phase in/out certain operations) by item revision or by change order, this capability is also provided.
The Routing can be defined at an item grouping level so that one isn’t required to develop a specific routing for each item yet can still gain the benefit of shop floor operation tracking for a given work order. Routings are also used in a Standard Cost Rollup to compute the labor, direct labor overhead, fringe overhead, machine overhead and subcontract labor cost components of the standard cost of the manufactured item.
Work Order Add and BOM Explosion
Typically the work order is added by MRP and then firmed by the material planner. However, the capability exists to manually add the Work Order in the Work Order Work Bench at a ‘firmed’ status. The user only needs to denote the Item, the Project (if project control is active), the Due Date and the Quantity (and if this is a special type of work order termed ‘rework order’ or ‘refurb order’).
The Work Order Work Bench enables the user to explode the Bill of Material. This process will use the derived scheduled pick date of the components and retrieve the effective bill of material and create work order demands, one for each component. The work order demand quantity required is calculated by multiplying the bill of material quantity per by the work order supply quantity required. There is additional capability to get bill of material ‘override’ information that will denote which work center components should be issued to, so that the work order demand will be added with work center ‘issued to’ information. (Operation Extract – below will link that work order demand to a work order operation). By using this capability the user can control the timing when material is move to the shop floor (only move it to the floor when needed in the manufacturing process).
Work Order Firm
Planned work orders generated by MRP can be firmed by the material planner. This action will indicate that the planner has taken control of this order and insure that MRP will not delete or modify this work order in the next planning run. MRP may make suggestions to the planner of required changes.
Work Order Release and Work Order Operation Extract
Prior to picking the material from stock, the work order is ‘released’ which is an indication that Production Control now supervises the management of the work order. As part of the work order release process, the work order operation extract will create the work order operations from the effective routing. If there are any work order component demands that designate that components are to be issued to the work center, as part of this extract the work order component demand will be linked to a work order operation.
Work Order Pick
The next step in the process is the Pick Process of components from stores. Production Control will denote that the work order is to be picked and a work order pick list for all components that are not backflushed will be made available to the store room for picking and sending to the shop floor. Stores will also record the quantity issued.
Work Order Time Booking
The direct laborer can record the times spent on an operation. These times are recorded in terms of hours (or fractions of hours). Machine times can also be recorded where appropriate.
Work Order Quantity Recordings
The quantity completed and moved to the next operation can be recorded. Based on the routing operation indicators, one transaction could be used to record both a ‘complete and move’ or one transaction can be used to record the ‘complete’ and a second to record the ‘move’.
Work Order Receipt and Backflush
The quantity that is completed at the last operation and is received into inventory is the Work Order Receipt. For those work order component demands identified as backflush items, the appropriate ‘work order demand issue’ from inventory will automatically be done as part of the work order receipt.
Work Order Cost
The work order contains all of the costs associated with material component issues and labor and machine time recordings. In a standard cost environment, the work order close process will compute the work order variance.