A method, device and equipment for critical task sequencing for planning scheduling

Abstract

The application relates to the technical field of intelligent manufacturing, in particular to a key task sequencing method, device and equipment for plan scheduling. The method comprises the following steps: merging global and grouping rules and standardizing according to a grouping context to obtain a standardized rule set; generating a key judgment value based on the rule set and writing the key judgment value into a key label based on the rule set matching a task to be scheduled; connecting a key comparison strategy to a first level of an access strategy chain; and sequencing the task to be scheduled based on the access strategy chain. The application solves the problem of rule conflict loss caused by a single format by merging global and line rules, significantly improves the flexibility of rule management, realizes linkage of identification and sequencing by writing the label into the task and connecting the strategy chain to the first level, ensures stable priority of key tasks, avoids performance overhead and inconsistency risk caused by repeated rule analysis in the sequencing stage, and finally realizes closed-loop management of configuration analysis, task labeling and sequencing priority.

Description

Technical Field

[0001] This application relates to the field of intelligent manufacturing technology, specifically to a method, apparatus, and equipment for sequencing critical tasks for planning and scheduling. Background Technology

[0002] Advanced Planning and Scheduling (APS) systems are used in the manufacturing industry to optimize process scheduling and resource allocation. The identification and prioritization of critical tasks are core factors affecting delivery cycles.

[0003] In existing technologies, tasks are typically defined by pre-defined rules and scheduled based on priority fields during the scheduling phase. However, existing critical task configuration schemes often rely on a single data format, making it difficult to support mixed configuration scenarios where "globally applicable rules" and "group-specific rules" coexist. This results in high rule migration costs and the potential for configuration overwriting or loss when multiple rules coexist, reducing the flexibility of rule management. Summary of the Invention

[0004] In related technologies, the critical task configuration scheme in the APS system relies on a single data format, making it difficult to support mixed configurations where global and group rules coexist. This can easily lead to problems such as rule overwriting or rule loss.

[0005] In a first aspect, embodiments of this application provide a method for prioritizing critical tasks in a planning and scheduling process, the method comprising: Global rules and group rules are merged according to the grouping context and then standardized to obtain a standardized rule set; Based on a standardized rule set, all tasks to be scheduled in the set of tasks to be scheduled are matched to generate key judgment values ​​for the tasks to be scheduled. Write critical markers into the tasks to be scheduled based on critical judgment values; Place the key comparison strategy at the top of the admission strategy chain; The tasks to be scheduled in the set of tasks to be scheduled are sorted based on the admission policy chain. In conjunction with the first aspect, in one implementation, the step of merging global rules and grouping rules according to grouping context and performing standardization processing to obtain a standardized rule set includes: Perform a union operation on the global rules and group rules under each group to obtain a set of group-level rules; A standardized rule set is generated by standardizing the set of group-level rules.

[0006] In conjunction with the first aspect, in one implementation, the step of matching all unscheduled tasks in the set of unscheduled tasks based on a standardized rule set to generate key judgment values ​​for the unscheduled tasks includes: Get the process number and group to which the task to be scheduled belongs; Retrieve the corresponding standardized rule set using the group to which the unscheduled task belongs as the index; Based on the corresponding standardized rule set, the process number of the task to be scheduled is matched and judged, and a key judgment value is generated according to the matching status between the process number and the standardized rule set.

[0007] In conjunction with the first aspect, in one implementation, generating a key judgment value based on the matching status between the process number and the standardized rule set includes: Determine whether the process number matches a rule in the standardized rule set; where, If a match is found, a first key judgment value representing the key is generated; If no match is found, a second key judgment value representing a non-key value is generated.

[0008] In conjunction with the first aspect, in one implementation, writing a critical marker into the task to be scheduled based on a critical judgment value includes: A key marker is generated based on the first key judgment value; if a task to be scheduled corresponds to multiple first key judgment values, the multiple first key judgment values ​​are merged to generate a unique key marker. Write the key markers into the corresponding tasks to be scheduled.

[0009] In conjunction with the first aspect, in one implementation, the step of inserting the critical comparison strategy into the head position of the admission strategy chain includes: The key markers are converted into numeric sort keys using a mapping function; The sorting key is used as the first-level comparison dimension of the admission strategy chain, and other business strategies are used as subsequent comparison dimensions.

[0010] In conjunction with the first aspect, in one implementation, the sorting of unscheduled tasks in the set of unscheduled tasks based on the admission policy chain includes: The tasks to be scheduled are sorted based on the admission policy chain. During the comparison process, the sorting key of the tasks to be scheduled is compared first. If the sorting keys are the same, other business policies in the admission policy chain are compared.

[0011] In conjunction with the first aspect, in one implementation, after sorting the tasks to be scheduled based on the admission policy chain, the method further includes: Record the entire data chain from generating a standardized rule set to completing the sorting; Audit logs are generated based on end-to-end data.

[0012] Secondly, embodiments of this application provide a critical task sequencing device for planning and scheduling. The critical task sequencing device includes: The rule processing module is used to merge global rules and group rules according to the grouping context and perform standardization processing to obtain a standardized rule set; The task tagging module is used to match all unscheduled tasks in the unscheduled task set based on a standardized rule set to generate critical judgment values ​​for the unscheduled tasks, and write critical tags into the unscheduled tasks based on the critical judgment values. The policy access module is used to access key comparison policies at the head of the admission policy chain. The sorting execution module is used to sort the unscheduled tasks in the set of unscheduled tasks based on the admission policy chain.

[0013] Thirdly, embodiments of this application provide a critical task sorting device for planning and scheduling. The critical task sorting device includes a processor, a memory, and a critical task sorting program stored in the memory and executable by the processor. When the critical task sorting program is executed by the processor, it implements the steps of the critical task sorting method as described in any of the preceding claims.

[0014] The beneficial effects of the technical solutions provided in this application include: This invention solves the problem of rule conflicts or loss caused by the reliance on a single format in existing technologies by merging global and production line rules according to grouping context, thereby improving configuration flexibility. By writing critical tags into task objects and connecting them to the head of the admission policy chain, it achieves close linkage between critical task identification and sorting execution, ensuring that critical tasks are consistently prioritized in scheduling, while avoiding the performance overhead and inconsistency risks caused by repeatedly parsing rules in the sorting stage, thus realizing closed-loop management of configuration parsing, task tagging, and sorting priority. Attached Figure Description

[0015] Figure 1 This is a flowchart illustrating an embodiment of the key task sorting method of this application; Figure 2 This is a schematic diagram of the hardware structure of the critical task sequencing device involved in the embodiments of this application. Detailed Implementation

[0016] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0017] In related technologies, the critical task configuration scheme in the APS system relies on a single data format, making it difficult to support mixed configurations where global and group rules coexist. This can easily lead to problems such as rule overwriting or rule loss.

[0018] In a first aspect, embodiments of this application provide a method for prioritizing critical tasks in a planning and scheduling process.

[0019] In one embodiment, reference is made to Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the critical task sequencing method for planning and scheduling in this application. Figure 1 As shown, the key task sequencing method for planning and scheduling includes: Step S1: Merge global rules and group rules according to grouping context and perform standardization processing to obtain a standardized rule set.

[0020] Specifically, step S1 above includes: Step S1a: Read global rules from the configuration source.

[0021] It should be noted that the global rules include a list of key process rules applicable to the entire plant.

[0022] Step S1b: Read the grouping rules according to the grouping context (workshop, production line, resource group, etc.).

[0023] It should be noted that the system pre-stores a global list of rules applicable to the entire plant, as well as a list of group rules divided by workshop, production line, or resource group.

[0024] Step S1c: Perform a union operation on the global rules and group rules under each group to obtain a set of group-level rules.

[0025] It's worth noting that in this step, global rules and grouping rules are no longer considered mutually exclusive. Instead, "grouping" is used as the context index, with global rules as the base set and grouping rules as the supplementary set, and a union operation is performed. For example, for "Workshop A," the final applicable rule set is a combination of "global rules" and "Workshop A specific rules."

[0026] Step S1d: Standardize the group-level rule set to generate a standardized rule set.

[0027] Understandably, after merging, the group-level rule sets undergo standardization, including unifying field names, standardizing encoding formats, removing duplicate rules, and identifying and ignoring illegal rules. Illegal entries are then written to the audit log without disrupting the main process. Through this step, each group has an independent and standardized rule set, avoiding rule overwriting or loss issues caused by a single configuration source. Simultaneously, standardization eliminates format differences between multi-source rules, allowing subsequent matching logic to disregard the rule source, reducing system maintenance costs and improving the standardization and compatibility of rule management.

[0028] Step S1e: Write the standardized rule set into the cache.

[0029] Step S2: Match all unscheduled tasks in the unscheduled task set based on the standardized rule set to generate critical judgment values ​​for the unscheduled tasks.

[0030] Step S2 above includes: Step S2a: Obtain the process number and group to which the task to be scheduled belongs.

[0031] Specifically, the queue of tasks to be scheduled is traversed. For each task to be scheduled, its group information (such as workshop ID) and process information (such as process number) are obtained first.

[0032] Step S2b: Obtain the corresponding standardized rule set using the group to which the task to be scheduled belongs as the index.

[0033] Specifically, the corresponding standardized rule set generated in step S1 is searched using the group to which the task to be scheduled belongs as the index.

[0034] Step S2c: Based on the corresponding standardized rule set, match and judge the process number of the task to be scheduled, and generate key judgment values ​​according to the matching status between the process number and the standardized rule set.

[0035] Specifically, the task's process number is matched against the rule conditions in the rule set. If the process number matches any rule in the standardized rule set, a first key judgment value (e.g., 1 or True) representing "critical" is generated; if no rule is matched, a second key judgment value (e.g., 0 or False) representing "non-critical" is generated.

[0036] Understandably, this implementation constructs a precise task-rule mapping relationship through the dual constraints of "the task's group as the index" and "the process number as the matching content." It utilizes the group context to quickly locate the applicable subset of rules, avoiding the computational overhead of traversing all rules, while ensuring that critical judgments are based solely on the specific context of the production line or workshop to which the current task belongs, thus improving the accuracy of critical task identification and the response speed of the scheduling system.

[0037] Step S3: Write critical markers into the tasks to be scheduled based on critical judgment values.

[0038] Understandably, writing key judgment values ​​into specific fields of the task object can avoid having to rescan the rule table for each subsequent priority comparison between tasks.

[0039] Furthermore, in real-world scenarios, a scheduled task may hit multiple rules simultaneously during rule matching in step S2 (e.g., it hits both global rules and group rules). This may generate multiple first key judgment values, which in turn will generate multiple key markers. In this case, a conflict resolution strategy needs to be executed.

[0040] Preferably, the conflict resolution strategy includes: if a task to be scheduled corresponds to multiple first key judgment values, then the multiple first key judgment values ​​are merged based on a preset fixed strategy (such as taking the maximum value, taking the minimum value, or fixed priority) to generate a unique key marker, and then the key marker is written into the corresponding task to be scheduled.

[0041] Understandably, for example, if a strategy of "any one hit is critical" is adopted, then the maximum value of all judgment values ​​is taken. After writing the final unique criticality tag into the task object, the system can directly read the tag within the current scheduling cycle without repeatedly parsing the rules, thereby reducing the computational overhead of hot paths.

[0042] Step S4: Connect the critical comparison strategy to the head position of the admission strategy chain.

[0043] It should be noted that advanced scheduling systems typically maintain an admission policy chain, which is used to compare the priorities of two tasks during sorting.

[0044] Furthermore, in one embodiment, step S4 includes: Step S4a: Convert the key markers into numeric sort keys using a mapping function.

[0045] Understandably, in this step, a mapping function is used to convert the critical markers in the task objects into numeric sort keys. For example, if the sorting rule is that smaller values ​​take precedence, then critical tasks are mapped to 0, and non-critical tasks are mapped to 1.

[0046] Step S4b: Use the sorting key as the first-level comparison dimension of the admission strategy chain, and use other business strategies as subsequent comparison dimensions.

[0047] Specifically, the comparison logic corresponding to the sorting key is dynamically inserted into the first level (head position) of the admission strategy chain. The original business strategies (such as delivery date priority, output value priority, etc.) are retained in the chain as subsequent comparison dimensions.

[0048] It is worth noting that the above steps, through the features of "mapping function transformation" and "first-level position access," achieve a deep integration of critical dimensions and the admission strategy chain. The technical effect lies in transforming abstract key markers into numerical keys recognizable by the sorting engine. By placing these keys at the head of the comparison chain, the algorithm logically ensures that critical tasks are always compared before non-critical tasks, while simultaneously preserving the optimization capabilities of subsequent dimensions (such as delivery time and cost) for non-critical tasks or equally critical tasks. This achieves a balance between priority assurance and fine-grained optimization.

[0049] Step S5: Sort the unscheduled tasks in the set of unscheduled tasks based on the admission policy chain. Specifically, after the sorting process begins, pairwise comparisons are performed on the tasks to be scheduled based on the constructed admission policy chain. During the comparison process, the sorting key (i.e., the critical dimension) of the tasks to be scheduled is compared first. Scenario 1: If the criticality sorting keys of the two tasks are different (for example, one is a critical task and the other is a non-critical task), then the sorting result is directly obtained, with the critical task taking priority; Scenario 2: If the two tasks have the same criticality sorting key (e.g., both are critical tasks), then continue to compare other business strategy dimensions in the admission strategy chain (e.g., compare delivery dates).

[0050] Understandably, this cascading comparison method ensures that critical tasks have absolute priority under all circumstances, while still enabling business optimization within groups of tasks with equal criticality.

[0051] Furthermore, in one implementation, after sorting the tasks to be scheduled in the set of tasks to be scheduled based on the admission policy chain, the method further includes: Step S6: Record the entire data chain from generating the standardized rule set to completing the sorting.

[0052] It should be noted that not only the final sorting result needs to be recorded, but also the rule ID hit by each task, the generated key judgment value, the conflict resolution process, and the final comparison path in the sorting chain.

[0053] Step S7: Generate audit logs based on end-to-end data.

[0054] Understandably, audit logs can be stored in a database or log file, supporting queries by task ID, time period, or rule ID. When disputes arise regarding scheduling results on the production floor (e.g., a critical task is not prioritized), managers can use the audit logs to trace back and check whether the task did not match a rule (marked as 0), matched a rule but was overridden by a higher-level policy in the sorting chain (this will not happen in this solution), or for other reasons. This implementation meets the compliance and traceability requirements in industrial scenarios, enhancing the system's credibility.

[0055] In summary, this invention supports a hybrid configuration mode of "global + group" by merging global and production line rules according to group context and performing standardized processing. This effectively avoids rule overwriting or loss, significantly improving the flexibility and migration efficiency of rule management. By merging key judgment values ​​into unique tags and writing them into task objects, this tag is reused in the sorting stage instead of repeatedly parsing rules, reducing computational overhead and ensuring execution consistency. By placing the key comparison strategy at the head of the admission strategy chain, absolute priority of key tasks in sorting is guaranteed, while retaining the fine-grained optimization capability of subsequent business strategies. In addition, combined with a standardized conflict resolution mechanism and full-link audit logs, the uniqueness and stability of the tagging results and the traceability of the scheduling process are ensured. Ultimately, a three-stage closed loop of configuration parsing, task tagging, and sorting priority is achieved, improving the compliance, credibility, and overall operational efficiency of the advanced planning and scheduling system.

[0056] Secondly, embodiments of this application also provide a critical task sorting device, which includes: a rule processing module, a task marking module, a strategy access module, and a sorting execution module; wherein, The rule processing module merges global rules and group rules according to the grouping context and performs standardization processing to obtain a standardized rule set. The task marking module matches all unscheduled tasks in the unscheduled task set based on the standardized rule set to generate criticality judgment values ​​for the unscheduled tasks and writes criticality tags into the unscheduled tasks based on the criticality judgment values. The policy access module is used to access the criticality comparison policy at the head position of the admission policy chain. The sorting execution module sorts the unscheduled tasks in the unscheduled task set based on the admission policy chain.

[0057] The functions of each module in the above-mentioned critical task sorting device correspond to the steps in the above-mentioned critical task sorting method embodiment, and their functions and implementation processes will not be described in detail here.

[0058] Thirdly, embodiments of this application provide a critical task sorting device, which can be a personal computer (PC), laptop computer, server, or other device with data processing capabilities.

[0059] Reference Figure 2 , Figure 2 This is a schematic diagram of the hardware structure of the critical task sequencing device involved in the embodiments of this application. In the embodiments of this application, the critical task sequencing device may include a processor, a memory, a communication interface, and a communication bus.

[0060] The communication bus can be of any type and is used to interconnect the processor, memory, and communication interface.

[0061] Communication interfaces include input / output (I / O) interfaces, physical interfaces, and logical interfaces used for interconnecting devices within the mission-critical sequencing equipment, as well as interfaces used for interconnecting the mission-critical sequencing equipment with other devices (such as other computing devices or user equipment). Physical interfaces can be Ethernet interfaces, fiber optic interfaces, ATM interfaces, etc.; user equipment can be displays, keyboards, etc.

[0062] Memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0063] The processor can be a general-purpose processor, which can call a critical task sequencing program stored in memory and execute the critical task sequencing method provided in the embodiments of this application. For example, the general-purpose processor can be a central processing unit (CPU). The method executed when the critical task sequencing program is called can be referred to in the various embodiments of the critical task sequencing method of this application, and will not be repeated here.

[0064] Those skilled in the art will understand that Figure 2 The hardware structure shown does not constitute a limitation of this application and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0065] Fourthly, embodiments of this application also provide a computer-readable storage medium.

[0066] The present application provides a computer-readable storage medium storing a critical task sequencing program, wherein when the critical task sequencing program is executed by a processor, it implements the steps of the critical task sequencing method described above.

[0067] The method implemented when the critical task sequencing procedure is executed can be referred to in various embodiments of the critical task sequencing method of this application, and will not be repeated here.

[0068] It should be noted that the sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0069] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.

[0070] In the description of the embodiments of this application, terms such as "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a concrete manner.

[0071] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.

[0072] In some processes described in the embodiments of this application, multiple operations or steps are included in a specific order. However, it should be understood that these operations or steps may not be executed in the order they appear in the embodiments of this application, or they may be executed in parallel. The sequence number of the operation is only used to distinguish different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed sequentially or in parallel, and these operations or steps may be combined.

[0073] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device to execute the methods described in the various embodiments of this application.

[0074] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A method for prioritizing critical tasks in a planning and scheduling process, characterized in that, The key task prioritization method includes: Global rules and group rules are merged according to the grouping context and then standardized to obtain a standardized rule set; Based on a standardized rule set, all tasks to be scheduled in the set of tasks to be scheduled are matched to generate key judgment values ​​for the tasks to be scheduled. Write critical markers into the tasks to be scheduled based on critical judgment values; Place the key comparison strategy at the top of the admission strategy chain; The tasks to be scheduled in the set of tasks to be scheduled are sorted based on the admission policy chain.

2. The critical task prioritization method as described in claim 1, characterized in that, The process of merging global rules and grouping rules according to grouping context and performing standardization to obtain a standardized rule set includes: Perform a union operation on the global rules and group rules under each group to obtain a set of group-level rules; A standardized rule set is generated by standardizing the set of group-level rules.

3. The critical task prioritization method as described in claim 1, characterized in that, The process of matching all unscheduled tasks in the set of unscheduled tasks based on a standardized rule set to generate key judgment values ​​for the unscheduled tasks includes: Get the process number and group to which the task to be scheduled belongs; Retrieve the corresponding standardized rule set using the group to which the unscheduled task belongs as the index; Based on the corresponding standardized rule set, the process number of the task to be scheduled is matched and judged, and a key judgment value is generated according to the matching status between the process number and the standardized rule set.

4. The critical task prioritization method as described in claim 3, characterized in that, The step of generating key judgment values ​​based on the matching status between the process number and the standardized rule set includes: Determine whether the process number matches a rule in the standardized rule set; where, If a match is found, a first key judgment value representing the key is generated; If no match is found, a second key judgment value representing a non-key value is generated.

5. The critical task prioritization method as described in claim 4, characterized in that, The step of writing critical markers into the tasks to be scheduled based on critical judgment values ​​includes: A key marker is generated based on the first key judgment value; if a task to be scheduled corresponds to multiple first key judgment values, the multiple first key judgment values ​​are merged to generate a unique key marker. Write the key markers into the corresponding tasks to be scheduled.

6. The critical task prioritization method as described in claim 1, characterized in that, The step of integrating the critical comparison strategy into the head position of the admission strategy chain includes: The key markers are converted into numeric sort keys using a mapping function; The sorting key is used as the first-level comparison dimension of the admission strategy chain, and other business strategies are used as subsequent comparison dimensions.

7. The critical task prioritization method as described in claim 6, characterized in that, The sorting of unscheduled tasks in the set of unscheduled tasks based on the admission policy chain includes: The tasks to be scheduled are sorted based on the admission policy chain. During the comparison process, the sorting key of the tasks to be scheduled is compared first. If the sorting keys are the same, other business policies in the admission policy chain are compared.

8. The critical task prioritization method as described in claim 1, characterized in that, After sorting the tasks to be scheduled based on the admission policy chain, the process also includes: Record the entire data chain from generating a standardized rule set to completing the sorting; Audit logs are generated based on end-to-end data.

9. A critical task sequencing device for planning and scheduling, characterized in that, The critical task prioritization device includes: The rule processing module is used to merge global rules and group rules according to the grouping context and perform standardization processing to obtain a standardized rule set; The task tagging module is used to match all unscheduled tasks in the unscheduled task set based on a standardized rule set to generate critical judgment values ​​for the unscheduled tasks, and write critical tags into the unscheduled tasks based on the critical judgment values. The policy access module is used to access key comparison policies at the head of the admission policy chain. The sorting execution module is used to sort the unscheduled tasks in the set of unscheduled tasks based on the admission policy chain.

10. A critical task sequencing device for planning and scheduling, characterized in that, The critical task sorting device includes a processor, a memory, and a critical task sorting program stored in the memory and executable by the processor, wherein when the critical task sorting program is executed by the processor, it implements the steps of the critical task sorting method as described in any one of claims 1 to 8.

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