Configure a fixed kanban rule

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Fixed quantity kanban

Fixed quantity kanbans are often used with fixed circulating cards but can also be used with single use cards. A fixed quantity kanban is a make-to-stock scenario.

Circulating and single use cards

For a circulating kanban card, the printed cards are reused and circle physically between the item origin and the point of consumption. After you define the kanban quantity, the needed cards are printed once.

Fixed circulating cards can move between item origin and point of consumption multiple times a day. This replenishment strategy is mostly applied between cells of one site that have physical proximity, for example, to replenish a cell supermarket out of the main material warehouse.

Kanbans that are created for single use can be used to cover additional demand to level specific exceptional demand. Only single use kanbans are always based on fixed quantity rules and no specific rules need to be created for this replenishment strategy. Instead, the kanbans have a flag that marks them as single use. You can also use event kanbans for exceptional demand above a certain quantity to maintain the buffer stock of a fixed quantity kanban.

Kanban quantity calculations

Determining the fixed kanban quantity is one of the most important tasks of kanban planning and is often one of the most difficult tasks to perform. Supply Chain Management can calculate the kanban quantity by taking forecast, current demand, and historical demand into account.

Kanban rule setup

A kanban rule is a material supply policy that governs process and transfer activities that are based on kanbans. A kanban rule defines the way in which an item is produced or transferred and links the item to the activities within the production flow.

Watch the following video to see a demonstration of kanban rule setup.

Kanban rules are linked to a specific version of a production flow because the kanban rules are linked to these activities to define how they produce or transfer the various items.

On creation, a kanban rule inherits the effective and expiration date of the production flow version. A kanban rule cannot be valid outside the validity period of the production flow version that it relates to. An expired kanban rule can have a replacing kanban rule that models the changed behavior for the product selection. The replacing kanban rule can be part of the same production flow version or the next production flow version.

When a kanban rule expires, the active kanbans of the expired rule are counted as kanbans of the replaced rule. When a kanban handling unit for an expired fixed quantity rule is registered as emptied, a new kanban is used for the replaced rule. The circulating cards of the replaced rule are similarly inherited to the replacing rule.

Go to Product information management > Lean manufacturing > Kanban rules to create new kanban rules.

The following list describes the fields in the Kanban rule FastTab:

  • Type - Specifies whether the kanban is a Manufacturing kanban that creates a kanban process job or a Withdrawal kanban that creates a kanban transfer job.

  • Replenishment strategy - Select Fixed when you are creating a fixed quantity kanban rule.

  • Kanban rule - Automatically assigned number that identifies the kanban rule.

  • Product selection - Identification of the product selection of the kanban rule. For a fixed kanban rule, this field is shaded.

  • First plan activity - Select the first activity of the kanban rule. This links the kanban to the production flow version activity. The first activity of a manufacturing kanban rule must be a process activity. The first and only activity of a Withdrawal kanban rule must be a transfer activity.

  • Multiple activities - Select this check box to configure multiple activities for the kanban rule. Only manufacturing kanbans can have multiple activities.

  • Last plan activity - When the Multiple activities check box is selected, you can select the last activity of the kanban rule. When Multiple activities is selected, the activity flow based on the production flow activity relations can be chosen to produce the kanban-specific flow. The lookup page displays all activities that are downstream from the first activity in the same production flow version.

  • Register as empty - Select an option to define when material handling units are registered as empty:

    • When handling units are received - When the last job of a kanban is completed, the kanbans are registered as empty and disappear from the kanban quantity overviews. This option the default setting for scheduled kanbans, and it can also be used for the other replenishment strategies. When this option is used with the fixed quantity strategy, a new kanban is created whenever the last job of the previous kanban is completed.

    • When the source requirement is registered - When the products that are supplied by event kanbans are consumed by the demand source, the kanbans are registered as empty. The kanbans disappear from the kanban quantity overview in the kanban boards.

    • Manual (includes scanning empty) - The kanbans must be explicitly registered as empty. Use this setting when products are stored in supermarkets before they are consumed or shipped. This option is the default setting for fixed quantity kanbans.

The following list describes the fields on the Details FastTab:

  • Product selection - Fixed quantity kanban rules must always specify a product selection of the type Product, and the product cannot have optional product dimensions.

  • Product - When the Product option is selected in the Product selection field, select the item from the lookup list. If the product carries product dimensions, the product dimension fields are activated. For fixed quantity kanban rules, the product dimensions are mandatory.

  • Product family - This field is not enabled for fixed quantity kanban rules.

  • Valid - Effective and Expires - Select the dates when the kanban rule becomes effective and when it expires.

  • Replaced rule - The rule that is used when a kanban rule expires. The rule can belong to the same version or a new version of the same production flow and needs to have the same item relation and last activity of the kanban flow.

  • Lead time - View the lead time that is needed to replenish the kanban. The lead time is the actual lead time that is agreed upon to replenish a kanban in a supermarket when the handling unit is empty. It is probable that the actual lead time is longer than the calculated lead time.

  • Unit of measure - The unit of measure that is used with the lead time. When the unit of measure is changed, the lead time is recalculated according to the defined conversion of the old and new units of measure. Only units of measure of the class Time can be used.

The following list describes the fields on the Quantities FastTab:

  • Default quantity - Enter the target product quantity to use for each kanban. This field is mandatory for fixed quantity rules.

  • Minimum quantity - This field is disabled for fixed quantity kanbans.

  • Maximum quantity - This field is disabled for fixed quantity kanbans.

  • Product quantity variance - On completion of a kanban job, a quantity tolerance can be set up for each kanban. Select this check box to allow the finished product quantity to differ from the specified product quantity for each instance of a kanban job that references the kanban rule.

    • Variance below - Enter the quantity by which the finished product quantity can be less than the specified product quantity.

    • Variance above - Enter the quantity by which the finished product quantity can exceed the specified product quantity.

  • Fixed kanban quantity - Enter the number of kanbans that are required to cover the forecasted demand during the validity period of the kanban rule. Kanban quantity calculations can be used to set the fixed kanban quantity. The calculation is based on actual demand, forecast demand, or historic consumption.

  • Alert boundary minimum - A visual alert can be set up for kanbans to show where planned kanbans are below a defined level. Enter a number of kanbans to define the minimum kanban quantity for each work cell or supermarket. When the number of jobs for active kanbans that are planned does not meet the specified minimum alert quantity, the background color is red instead of green. Active kanbans can have any handling unit status except Empty. The kanban rules are sorted by planning importance based on this alert boundary minimum.

  • Alert boundary maximum - Enter a number of kanbans to define the maximum kanban quantity for each work cell or supermarket. This boundary helps to visualize excess inventory in a supermarket. It also gives a visual signal when more scheduled or event kanbans than expected are created for a kanban rule.

  • Automatic planning quantity - To automatically plan a kanban instead of manually loading it onto a work cell, an automatic planning quantity should be set. Enter the number of unplanned jobs that cause automatic planning to occur. An unplanned kanban job has the status of not planned.

  • Maximum planned jobs - This field is disabled for fixed quantity kanbans.

The following list describes the fields in the Kanban and cards FastTab:

  • Card number sequence - The kanban card number sequence that is assigned to this kanban rule. When a kanban rule is created, the default number sequence from the production parameters is used.

  • Automatic printing - Select the event that causes automatic printing of kanban cards. The options are:

    • None - Automatic printing is not used. We recommend that you use this setting when circulating cards or electronic kanban processing is used.

    • Creation - Print kanbans when the kanban is created. We recommend that you use this setting when a physical planning board for event kanbans is used and circulating cards cannot be used.

    • Plan - Print kanbans when the first job of the kanban is planned. We recommend that you use this setting when a printed kanban card triggers the processing of kanban jobs on the shop floor.

    • Prepare - Print kanbans when the first job of a kanban flow is registered as prepared.

    • Start - Print kanbans when the first job of a kanban flow is registered as in progress.

    • Receive - Print kanbans when the first job of a kanban flow is registered as completed. This option is often used if batch or serial numbers of the finished items are printed on the kanban card.

  • Print picking list with card - Select this check box to print the picking list with the kanban card.

  • Kanban print instructions - Select the information to print on the kanban card. The options are:

    • Work instructions - Print the production instructions document that is attached to the kanban.

    • Shipping instructions - Only used for event kanbans.

  • Circulating cards - Select this check box to use circulating cards with the current kanban rule.

  • Number of active cards - Enter the number of active circulating cards that are in circulation at a given time for the kanban rule.

  • Card assignment - Select the method of assigning circulating cards. The options are:

    • Automatic - When a kanban is created, a card is assigned automatically when these conditions are true: an unassigned active kanban and an unassigned active card exist for a kanban rule. This setting is default.

      When kanbans are created before circulating cards are created, the cards are assigned automatically when the cards are created. If there is a shortage of cards, when a kanban is registered as empty, the card is automatically assigned to a new kanban. This is especially useful when circulating cards correspond to a limited number of conveyers, racks, or bins.

    • Manual - You must assign a card manually on the Kanban board. You can do this when you prepare a kanban job.

    • Single use kanbans use circulating cards - For fixed quantity kanban rules, select this check box to use circulating cards with single use kanbans. When the check box is not selected, single use kanban cards are created for single use kanbans. Circulating cards are then reserved for use with kanbans that are not created for single use.

The following list describes the fields in the Production flow FastTab:

  • First activity - View the production flow and version that the first activity references. If there are no kanbans created for this rule, you can edit this field in the activity lookup page.

  • Last activity - View the production flow and version that the last activity references. If no kanbans are created for this rule, you can edit this field in the activity lookup page.

  • Inventory transactions - This option is enabled if the first activity, last activity, or both activities of the kanban rule are configured to create inventory transactions. This field is automatically selected based on the activities in the production flow version.

  • Financial transactions - This option is enabled automatically when the kanban rule creates inventory transactions and one or more of these conditions are true:

    • The kanban type is Manufacturing.

    • The kanban type is Withdrawal, and the picking and receipt locations are managed by subcontractors.

    • The kanban type is Withdrawal, and the picking and receipt locations are on different sites.

      • The picking activity updates the on-hand inventory, and the receipt does not update on-hand inventory but is transferred to work in process (WIP).

      • The picking activity does not update on-hand inventory, but the receipt is transferred from WIP and does update on-hand inventory.

  • Kanban flow defined - This option is enabled when a valid kanban flow is defined for the kanban rule. The kanban flow defines the specific activity flow that this kanban rule goes through if multiple activities are selected.

  • Warehouse - View the warehouse where products are supplied.

  • Location - View the location where products are supplied.

The following list describes the fields in the Kanbans FastTab:

  • Kanban - The identification of the kanban.

  • Item Number - The item number and any product dimensions that are selected in the Storage dimension groups page that describes the product that is replenished by the kanban.

  • Product quantity - The product quantity that is replenished by the kanban.

  • Handling unit status - The status of the material handling unit that references a kanban. The handling unit status is determined by the corresponding kanban job status. The handling unit status is assigned automatically. The options are:

    • When the Handling unit status is Not assigned and the job status is Planned or Not planned, the first job is not prepared or started.

    • When the Handling unit status is Assigned and the job status is Prepared, the material for the first job is picked. The handling unit is prepared and a kanban card must be assigned.

    • When the Handling unit status is Received and the job status is Completed, the output from the last job is received at the incoming warehouse.

    • When the Handling unit status is Empty, the output that is supplied by the kanban is consumed. The handling unit is now empty. Circulating cards are unassigned and reused.

Kanban job planning

Supply Chain Management provides several methods to support planning kanbans for various production scenarios in Lean manufacturing. Kanbans do not have to go through a manual planning process, but rather can be automatically planned onto the work cell. Various options exist to help support common planning scenarios such as automatic planning, Kanban schedule boards, and Heijunka leveling.

For fixed quantity kanbans, a planned kanban based on this replenishment strategy cannot be manually firmed, because kanbans are only re-created based on consumption. The initial number of kanbans is defined manually or calculated based on the kanban quantity calculation.

The following sections discuss planning kanbans and the mechanism to plan these kanban jobs on the Kanban schedule board.

Planning a process kanban job

The three possibilities to plan and/or prioritize a kanban job are:

  • Plan manually in the Kanban schedule board - The Kanban schedule board allows leveling and planning for a number of days or weeks ahead (depending on the period type that is related to the Lean production flow model).

  • Automatic planning based on the automatic planning quantity - Whenever the number of unplanned jobs corresponds to this level, the automatic planning method is called for that exact number of kanbans.

  • Denote a kanban as a priority kanban on the Kanban board for process jobs.

When the process job is not planned, the estimated start date and time of the job is determined out of the due date of the kanban based on the kanban flow entries that describe the various activities that the kanban goes through.

The Due Date of the process job is calculated as follows:

Due Date of the process job = Due date of the Kanban - sum of all the lead times of all activities of the kanban flow after the process

The planned period date of the job is set when the job is planned; it holds the start of the planning period.

Work cell capacity

A kanban job is planned by assigning it to a period and a sequence within the period on a work cell.

The period types and the number of periods are defined on the resource groups on the Work cell capacity FastTab. The defined capacity will show as the available capacity for the period on the Kanban schedule board and will be consumed as automatic, and manually scheduled kanban jobs are loaded onto the schedule for that work cell.