Job Shop Scheduling

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Scheduling Systems

Scheduling systems take on many shapes and sizes.  In the age of computers we have the ability to create schedules for many different types of industries including

  • Appointment Scheduling
  • Job Shop Scheduling
  • Flow Control Scheduling
  • MRP Scheduling
  • ERP Scheduling
  • Sports Team Scheduling

The goal behind any type of scheduling system is to efficiently schedule a set of finite resources to their full capacity.  This is at least the main goal behind scheduling in manufacturing systems and software.  The other big benefit of scheduling systems is the ROI of having the computer manage all the appointments, team schedules without calculating the schedules by hand.

Job Shop Scheduling Systems is what MIE Solutions handles best.  If you are a job shop you can use MIE Trak to scheduling your company resources most efficiently so please visit us at

http://www.mie-solutions.com for more information

February 4, 2011 Posted by | Scheduling | , , , , , , , , , , , , , , , | Leave a comment

Job Shop ERP Calendar

ERP systems provide a variety number of ways to model the available capacity of resources.  There are basically two ways to do this, either a simplistic approach or a more comprehensive approach.

Simplistic Approach

The basic or simplistic approach is where there is one shop calendar which specifies the available days and hour per day with possible exceptions.   An example would be an organization works for 8 hour days monday through Friday.  This calendar can be be broken into smaller units of five, ten or 15 minutes to even an hour.  A global company wide calendar would accomplish this simplistic approach but the system is not very refined.  A refinement to this calendar can be that each scheduling resource may have its own calendar.   Each individual set of resources would then be able to specify variations to a standard calendar including days off, holidays and shut downs for repairs.

Comprehensive Approach

A more comprehensive approach is to use shift schedules.  A shift schedule defines start and end times of each shift and possible times between shifts throughout a 24 hour day.   Shifts a assigned independently of resource and then assigned to resources.   A global scheduling calendar is still required but each resource can be assigned a set of shifts.   As required through the use of exceptions, shifts can be assigned specific days in order to manage exceptions to the standard shift schedule.   A shift approach allows for other capacity scheduling requirements such as shift efficiencies and available head count.

Resource Types

There are various resource types which can associated to a calendar including employee’s, machines and even groups of machines.

MIE Trak supports your scheduling needs so please visit us at

http://www.mie-solutions.com for more information

April 12, 2010 Posted by | Uncategorized | , , , , , , , , , , , , , , , | 1 Comment

Finite Capacity Scheduling

Finite Capacity Schedule

Finite capacity scheduling is different and has different purposes then infinite schedule.  Finite capacity scheduling is when the allocation of resources is taken into account during the scheduling process.  Finite  capacity scheduling is scheduling only to the capacity available on the resources available.

There are many ways to schedule and finite capacity scheduling is just on of the methods used to try to control manufacturing processes.

Electronic scheduling board

The simplest way to scheduling is with an electronic scheduling whiteboard.   This method mimics the white board that took up an entire wall of the office prior to the introduction of computers.   Computer software can enable you to schedule by moving jobs to their appropriate resources manually and loading each of the resources finite.   This method gives total control to the production planner but it is limited on what can be scheduled for a particular time frame.  There is no real scheduling algorithm going on here but more of a gut feeling.   If with a electronic software scheduling white board estimated times and resources must be investigated for accuracy or the entire schedule is pointless.

Order Based Scheduling

Order based scheduling takes tasks based on a specified priority like due date, estimated hours, priority and schedules the tasks for each order.   Each task sequence is scheduled and as tasks are scheduled in a finite manner the resource usage grows.  If the resource is as capacity when a task sequence needs to be scheduled the task sequenced is pushed to the next available time / resource slot.   This type of scheduling gives a lot of gaps in resource allocations unless an iterative approach is used to fill the gaps more efficiently.

Algorithms, Genetic algorithms

Genetic algorithms are very complicated and are very mathematically intensive.  The area of study in genetic finite scheduling is continuing to grow and mature as more information is gained.   The use of genetic algorithms takes the idea of a ‘fitness’ criterion.  As task sequences are placed on resources, the task sequence is given a fitness value. This value is then compared to other task sequences requiring the same resource.  The resource allocation is adjusted based on the fitness values and the lowest fitness score loses.  This is sometimes considered survival of the fittest.

MIE Solutions, Inc. has been selling, consulting and creating software for finite and infinite capacity based scheduling systems for 20 years.  MIE Trak began as a DOS PC based system and worked its way up through the years to a full easy to use windows based software package.   MIE Solutions specialized in quoting, estimating, order entry, work orders, scheduling, purchasing, invoicing, job tracking, data collection to improve manufacturing on-time performance.

MIE Trak has been applied successfully in discrete, repetitive, process, engineer to order and assemble to order manufacturing.

Our primary focus is scheduling a job shop which can actually be used by the shop floor.   So many scheduling systems do not take into consideration changes and job collection during the scheduling process.   Schedules in a job shop can change hourly and management needs to make the appropriate adjustments as quickly as possible.

MIE Trak supports your scheduling needs so please visit us at

http://www.mie-solutions.com for more information

January 6, 2010 Posted by | Scheduling | , , , , , , , , , , , , , , , , , , | 1 Comment

Advanced Planning Finite Capacity Scheduling

Advanced planning and finite capacity scheduling accurately model manufacturing capacity of your factory. Your supply of capacity is based on shop calendars, holidays, work centers, labor, employees, tooling, floor space and any other resource which can constrain your production.  Job shops scheduling can be used for made to order and engineer to order but also can be used in production lines.  Many shops also need to express labor skill cross-qualifications, and tooling preferences to accurately define true “shop capacity”.

Advanced planning and scheduling (APS) adds the ability to schedule material and 3rd part processes to the scheduling process. This includes recognition of inventory, material pegged to production orders, open purchase orders, bills of material, and sales orders.

The goals of scheduling is to provide accurate and unparalleled scheduling integrating material planning and capacity planning, Delivering accurate estimates and ease of use tracking with bar coding or MIE Kiosk terminal to update the scheduling system is a requirement.   These elements help you achieve accurate visibility of order start and finish with ample time to take corrective action to prevent late deliveries and material stock-outs.  MIE Trak scheduling gives the following abilities to accomplish these goals:

  • model production capacity accurately;
  • create schedules consistent with your shop’s true capacity;
  • increase schedule visibility across sales, engineering, purchasing, production, shipping and customer service.
  • increase plant throughput by least 5-10% with the same labor giving profit gains of 8-12% for the company;
  • reduce schedule conflicts, overtime, outsourcing, emergency freight, crisis expediting; and
  • increase your competitiveness by improving your on-time performance.

Precision Scheduling reduces planning effort, because schedules become more stable once bottlenecks and major crisis points are anticipated and solved before they even become headaches.  Because short-range schedules accurately consider a greater number of constraints, production flows more smoothly, and issued inventory is tightly coupled to actual production.

MIE Traks advanced planning and scheduling  (APS) extends elementary finite scheduling systems by recognizing additional constraints. Recognizing constraints is an important factor to deliver a quality schedule which a shop could move parts through the plant.  Imagine having your shop follow a detailed schedule over the next 72 hours where the schedule has accurately allowed not only for just machine capacity, but has also considered labor attendance (including vacations), labor skills, tooling, floor-space, assembly sequences, and especially raw material availability.

MIE Trak can recognize on-hand inventory materials, open purchase orders, and planned allocations of material to work orders or shop production lots. Inventory levels move up and down across future scheduled days, recognizing every material receipt and issue event.  The material planner’s post-schedule analysis starts right from a list of simulated future net requirements. One of the key areas to improve the shop schedule is the ability to make adjustments and globally reschedule the shop to see the net changes.

Our latest product, MIE Trak continues to push the state of the art.  Its main advantages include:

  • Fast scheduling
  • Supports Labor, Labor Groups
  • Supports Assembly-Subassembly Synchronization
  • Supports Multi-Cell and Multi-Plant manufacturing environments.
  • Exact setup matching option based on part, part-family, color or other user-defined traits per operation.
  • Advanced Sequence Matching, with multiple trait families, and prioritization within each family.
  • Advanced Schedule White Board, showing both work station task time blocks and the matching resource assignments
  • Multiple Feature/Price Levels to best serve small to mid-size manufacturing companies.
  • Fully integrated Job Quote module, Capable to Promise visibility of achievable due-date quotes for customers.
  • Many standard reports which can be customized
  • What-If Comparisons, Un-used Capacity, Alternate Schedule Scores
  • Assign work to specific employees
  • 6 Methods of global scheduling from finite forward to infinite backwards.

MIE Traks job shop scheduling system fully supports the philosophy of lean manufacturing by recognizing that lean manufacturing covers a wide range of disciplines.  MIE Trak complements Lean Philosophy.  MIE Trak recognizes links between inventory, work centers and cells.   MIE Trak provides the  detailed scheduling that Lean Manufacturing needs especially to manage variable demand value-streams. MIE Trak also supports Just-in-Time scheduling, and ‘order-less’ batch-scheduling for repetitive make-to-stock companies.  MIE Trak is a strong mixed-mode scheduling system, used extensively in  job-shops, engineer-to-order and assemble to order shops, and can also be applied in repetitive make-to-stock shops which are partially ‘make-to-order’.

Jobs Sharing Same Resource (Nesting)

Batch Processing is a easy to use in MIE Trak.  Batch processing is used in MIE Trak how a nesting system works.  Nesting is when you place more then 1 job on the same machine at the same time in order to optimize setup, run, and material utilization.  Flexible Machining Systems using the nesting package allows multiple work orders to share the capacity of a single resouce, to satisfy the minimum daily shipments needed for multiple clients. MIE Trak supports this requirement of Flexible Machining Systems (FMS).

MIE Trak is a leading provider of prodution control software for the entire manufacturing sector.  Incorporating Fabrication Software, sheet metal software, machine shop software, ERP software, manufacturing software systems, estimating softwre, maintenance software, CMMS software, job tracking software, scheduling software, management software and job shop software.

For Finite Capacity Scheduling, typical resource capacity limits include the following:

  • Working calendars express working days of the week, shift lengths, and the starting time of each shift.  Holidays and other non-working days are also expressed in each calendar.
  • Work Centers defined as groups of like work-stations.  Work Centers include machines, equipment and work stations, but can also be used to model generic labor pools.
  • Secondary Resource constraints apply to labor, equipment, floor space, consumables.  Labor can also be designated by shift, also by qualified skills for a given resource group. This concept is extended to tool ‘qualifications’ to recognize subsets of tools of varying size, capabilities or power.

MIE Trak helps schedulers build an accurate model of your capacity demands and the resource limits in your shop.  By “accurate” we mean  shop conditions which include, but are not necessarily limited to the following examples:

  • Alternate routings: only specific subsets of your work stations, tools or operators are qualified to perform certain operations.
  • Operations have both a fixed setup/teardown time as well as a quantity based time per-unit for processing time.
  • Multiple resource constraints demanded by the same operation such as labor, tools, floor space, water, power, lubricants, raw materials, etc.
  • Easy modeling of overlapping tasks to maximize ‘Just-in-Time’, Parallel, From-Start, and activity branches inside each work order.
  • Assembly links between work orders to correctly model assembly manufacturing
  • Recognition of a variable crew size per operation.
  • Recognition that a single operator can simultaneously be tending N number of machines.
  • MIE Kiosk (White Board, Kiosk) Schedule Board which shows both machines and assigned labor and tooling resources per task
  • Explicitly splitting operations across multiple work stations of the work center to saturate available capacity.
  • Resource seized and held across a series of operations, such as a special vice, cart, tool or even the same manager or operator set.

MIE Solutions, Inc. has been selling, consulting and creating software for finite and infinite capacity based scheduling systems for 20 years.  MIE Trak began as a DOS PC based system and worked its way up through the years to a full easy to use windows based software package.   MIE Solutions specialized in quoting, estimating, order entry, work orders, scheduling, purchasing, invoicing, job tracking, data collection to improve manufacturing on-time performance.

MIE Trak has been applied successfully in discrete, repetitive, process, engineer to order and assemble to order manufacturing.

MIE Trak also offers a full range of services including:

  • analysis of situation,
  • modeling,
  • training,
  • customization,
  • implementation support, and
  • measurement of benefits.

Our primary focus is scheduling a job shop which can actually be used by the shop floor.   So many scheduling systems do not take into consideration changes and job collection during the scheduling process.   Schedules in a job shop can change hourly and management needs to make the appropriate adjustments as quickly as possible.

MIE Trak supports your scheduling needs so please visit us at

http://www.mie-solutions.com for more information


December 20, 2009 Posted by | Uncategorized | , , , , , , , , , , , , , , , , , | Leave a comment

Job Shop Software Scheduling Cycle Time

Scheduling software systems, both finite and infinite, need to take into account both setup time and cycle time.   One of the most difficult aspects of scheduling is creating an accurate estimating of what the cycle time may be for a process.   If you estimate for the cycle time is not accurate your scheduling system will not be accurate.  There are many factors which affect the cycle time which are not fixed including skill level of the person running the machine, reliability of the machine, maintenance of the machine, inspection of the parts being run, the quality of the material and others.

Cycle time is defined as the handling time + run time.

Handling time is the time spent as the operator loads and unloads the part being manufactured from the machine.

Run time is the time the operator spends at the machine running the part or the time the machine is running by itself, i.e. a cnc machine.    Some operations require the operator to be present during the running of the part and others do not.

When scheduling software is calculating resource requirements it is not usually differentiating the handling and run time but there are situations where this should be addressed.   If the run time is very lengthy and a machine is running it independently then the only resources being consumed is the machine and not the employee.   The employee would only be involved in the handling of the material to load and unload the machine.  In this situation the scheduling software may actually scheduling the job shop differently then if it was only looking at machine resources.   The scheduling software needs to be able to schedule both the handling time and the run time which is the cycle time.

Estimating your cycle times is a critical area for any manufacturer to be profitable and also to have an accurate schedule.    Cost estimating MIE Solutions provides software to help you do this calculations as efficiently as possible through their MRP/ERP systems quoting package.

http://www.mie-solutions.com/mie/index.php/MIE-Trak/

http://www.mie-solutions.com/mie/

December 20, 2009 Posted by | Scheduling | , , , , , , , , , , , , , , , , , , , | Leave a comment

ERP Scheduling With Setup Time

MIE Solutions offers a made to order job shop ERP system designed for the manufacturer of goods and products.  MIE Trak is a full featured ERP system for the made to order and engineer to order manufacturer.

Scheduling Machines For ERP Systems

Scheduling machines requires an initial understanding of the estimated hours jobs take to produce.   If you estimated hours for both setup and run are incorrect your scheduling system will only produce poor results.   The results of your scheduling system are based on how accurate your estimates are.

Setup Time
Setup time is the time it takes to make the first accepted piece which includes bringing all the tools, jigs and fixtures, setup those jigs and fixtures for a particular batch quantity.   Operation run time or cycle time, is the time spent to complete each unit through the machine.  Setup time can be simple or complex and it really depends on the process being performed.   Setup time is usually independent of the actual run time because once a machine is setup it can be continually run without setting the machine up a second time.  Setup time is a key component to scheduling in ERP systems.  Setup time can actually be broken down into a few categories.
Staging Time
The time required to gather materials, dies or any other equipment required to get the machine running.   Staging can potentially be performed during the running of another job through the machine because it may not actually require the machine to be available.   A simple definition is time spent on a machine or process prior to a manufacturing run. Staging time is important part of a scheduling system because this can actually be executed concurrently with cycle time.
Setup Time
The time required to bring this production batch quantity to an actionable state.
Transit Time
Transit time is the time to move a particular batch quantity to another step in the process.  Transit time is important part of a ERP scheduling system because this can actually be executed concurrently by another employee or the same employee during the cycle time as parts are being completed.  Another area would be after a job has been completed at a machine, the machine setup for the next job could take place as parts are moved to their next machine for processing.
Tear Down Time
The time required to remove all the equipment that was required to be setup on the machine making it ready for the next process.   A job may continue to the next operation during the tear down time because this time does not affect the actual job, only the machine.   A simple definition is the time to take down a machine or process after a manufacturing run.   Tear down time is important part of ERP scheduling system because this can actually be executed as the next sequence step for the job is progressing.   Tear down time will not allow the machine to be used by another job until the conclusion of the tear down time.
Quoting and ERP packages should provide the capability for these setup time variations in order to allow your estimating , costing and even scheduling to be as accurate as possible.  ERP packages need to take into account these areas to accurately schedule your job shop and make most efficient use of your machines and resources.

MIE Trak has an advanced scheduling system which includes both finite and infinite scheduling.  MIE Trak is designed for most any type of job shop include made to order and engineer to order production organizations. You can visit the website at

http://www.mie-solutions.com

December 14, 2009 Posted by | Scheduling | , , , , , , , , , , , , , , , , , | Leave a comment

ERP Job Shop Resources Employees and Machines

For manufacturing planning and scheduling systems that consider capacity leveling, production data is plugged into equations that result in two types of schedules: Those based upon the known real-time data of existing work loads, emerging jobs, material, machines, and labor (finite scheduling); and, those schedules for orders and operations that ignore all existing and/or future resource loads (infinite scheduling). In either case, for the most dynamic creation of finite or infinite scheduling a powerful enterprise resource planning software program (ERP) is needed to factor a wide range of production data and variables.
For a variety of reasons, some manufacturers prefer to schedule jobs according to the limitation of resources and capacity found within their system. Scheduling processes that, from the outset, take the limited capacity of a plant to produce are said to be using a finite approach to scheduling management. For the manufacturer, this approach works a schedule according to capacity criteria set in advance of production. The criteria can include any number of factors such as job due dates, job importance, and even the very importance of the customer to the manufacturer. Finite scheduling means that you are more often than not running your most important jobs first, getting them out as close to the promised delivery due date as possible, while hoping to return to less vital jobs in due time.
There are a number of ways to determine this concept of “importance” when it comes to finite job scheduling. In the most simplest terms, a manufacturer can schedule merely according to how much a plant is capable of producing in any one average workday. That is to say, how much can be produced without the need for additional machinery, manpower, or other resources? Often, this technique employs electronic scheduling boards, which tend to copy the old card-based loading boards and calculate time and machinery automatically so that no two jobs are loaded on the same machine at the same time. In this way, production is limited through finite scheduling that recognizes limited capacity.
On the other hand, scheduling can be done based upon priority criteria. Finite techniques such asorder-based scheduling produce tasking lists on the basis of order priority. The router sequence for individual resources is determined by the overall priority of the order for which the parts are destined. Here, jobs may be deemed “important” by their relationship to other jobs in assembly modes, the sudden availability of usually limited materials, and/or the customer value to the company of the client placing the order. While this technique can prove to be a more accurate way of producing scheduling algorithms, the concept does open up the possibility for some work centers to go under utilized due to gaps in the schedule to accommodate idiosyncratic router sequencing.
Finally, constraint-based scheduling is a finite method that works through a Master Production Schedule to locate the bottleneck in the line and continue to load it. In short, constraint-based scheduling will try to synchronize, or “balance”, the bottleneck with non-bottlenecks along the line and in this way have a more accurate determination of when bottleneck items will be ready. As afinite concept used in enterprise resource planning (ERP) software, constraint-based scheduling has become interesting as a form of modeling and solving scheduling problems. With a robust ERP system, it is now possible to run constraint-based schedulers on-line for any number of parts and assemblies.
For manufacturing planning and scheduling systems that consider capacity leveling, production data is plugged into equations that result in two types of schedules: Those based upon the known real-time data of existing work loads, emerging jobs, material, machines, and labor (finite scheduling); and, those schedules for orders and operations that ignore all existing and/or future resource loads (infinite scheduling). In either case, for the most dynamic creation of finite or infinite scheduling a powerful enterprise resource planning software program (ERP) is needed to factor a wide range of production data and variables.
In an ERP operation where accurate scheduling is a vital part of the strategy for on-time delivery, a robust scheduling software program is needed that is flexible enough to provide both finite and infinite scheduling quickly and accurately. In short, master schedulers must be able to answer the typical questions that face them everyday, such as: “Can we accomplish this forecast?”, “In which work center should we run this production?”, and “When should we promise the delivery for a customer’s order?”. To achieve accurate answers to these questions, schedulers must have access to real-time data from all aspects of plant operations.
Therefore, the smooth flow of data throughout a manufacturing operation is needed for scheduling. A fully implemented ERP software offers such a data integration platform that can make a significant difference in the accurate scheduling necessary for the all-important consistent on-time delivery. For example, perhaps the greatest function of ERP scheduling is its ability to tell shop floor operators the next job in line to be performed. Often utilizing an easy to use Graphic User Interface (GUI) viewer screen, operators can see not only which jobs or specific job functions are scheduled next, but they can also view online assembly and quality instructions, and even schematics and photographs of what the finished piece should look like.
In addition, ERP software can be used for supply chain management as a global scheduling and rescheduling tool for multiple locations throughout the supply chain and plant work centers. In other words, for finite scheduling, ERP software provides real-time assessment of present and short-term plant capacity as defined by on-hand manufacturing resources (material, machines, labor, etc.). Such finite scheduling methods are necessary when the manufacturer must deal with the potential of running hundreds of jobs and thousands of events each day, where tracking individual job progress can often be quite difficult. With the GUI, each job status is easily and instantly available to all shop personnel.
However, when a manufacturer wishes to look out into the future to determine the production possibilities that could occur in best (or worst) case scenarios, master schedulers can load capacityinfinitely. In other words, the planning system assumes that, at any given time, the plant will have the resources necessary to do any work presented to the operation. That is, in infinite scheduling and planning the assumption is that plant resources (labor, machinery, material, etc.) have infinite capacity. With the GUI, master schedulers can load into the ERP system any number of data level types set to infinite capacity and ascertain potential physical plant and personnel needs in various hypothetical economic scenarios, over any desired period of time.
In conclusion, whether operational needs are for scheduling jobs in either an infinite or finite capacity, a fully implemented ERP software solution is necessary to keep up with and assess the consistent flow of production data flowing through a plant. The more robust the ERP software, the more accurate the real-time picture of present and/or future plant capacity.

MIE Solutions offers a made to order job shop ERP system designed for the manufacturer of goods and products.  MIE Trak is a full featured ERP system for the made to order and engineer to order manufacturer.

In a manufacturing facility there are two sets of finite resources, machines and people.  I say these are finite resources because you do not have infinite capacity of these resources.   Lets discuss the two types of resources

Employee As Resources

Employee’s are the first type of resource that we will be discussing.  Employee’s work a specific number of hours each day, week, month and year.   Each individual employee is a resource with a specific capacity.   An employee resource needs to have specified how many hours on each individual day that employee is able to work.   Employee’s are a unique type of resource unlike most machines, employee’s can do multiple types of jobs.  Employee’s can also do multiple jobs simultaneously and run multiple machines simultaneously.  In most situations employee’s themselves are using other resources, i.e. machines in order to get their job done.   Therefore each step of a job process may take multiple resources at the same time.   Not all jobs require both an employee and a machine resource, some jobs require just an employee, i.e. assembly.

Machines

Machines are the second type of resource.  Machines are assets (not employee’s) that perform work for a specific number of hours each day, week, month and year.   Each machine is a resource with a specific capacity to do work. Many times you could group common machines into work centers which have capacity.  Each machine in a work center group needs to have its own hours of operation.   Machines are also unique because machines can run without an employee resource involved, machines can run one to one with an employee resource or a machine can run with multiple employee resources simultaneously.    Example of a machine running by itself would be a dryer.  A dryer is loaded by an employee resource but the dryer mainly run unattended.   An example of a machine that is one to one with an employee resource would be a non automated welder.  A welder’s equipment and a welder would be a one to one resource situation.   A final example of a machine which requires multiple employee’s would be a large press where there could be 2 or more employee’s participating in the usage of the machine.

There are a lot more details which we will cover in future blogs discussing resources for scheduling.   Sheet metal job shops, stamping houses, assembly houses, machine shops all have the need to schedule resources to make best use of their equipment and manpower.

MIE Trak has an advanced scheduling system which includes both finite and infinite scheduling.  MIE Trak is designed for most any type of job shop include made to order and engineer to order production organizations. You can visit the website at

http://www.mie-solutions.com

September 15, 2009 Posted by | Uncategorized | , , , , , , , , , , , , , , , , , , | Leave a comment

Finite and Infinite Scheduling

MIE Solutions offers a made to order job shop ERP system designed for the manufacturer of goods and products.  MIE Trak is a full featured ERP system for the made to order and engineer to order manufacturer.

ERP software used for manufacturing planning and scheduling systems must consider capacity leveling.   Capacity leveling is basically done in one of the two main flavors of scheduling.

  1. Finite Schedule
  2. Infinite Scheduling

Each of these two flavors of scheduling of jobs have many variations but the general rule of thumb is true.

Finite scheduling is where jobs are scheduled according to the limitation of resources and capacity found in the production environment.   Scheduling processes that take into account a set of finite resources is basically a finite scheduling process.

Infinite scheduling is where jobs a scheduling not according to the limitation of the finite resource, but the scheduling process schedules making the assumption no other activity is using the finite resources.  I like to think of infinite scheduling as a system where there are no other jobs or activities being scheduled except the single job or activity.   Infinite scheduling basically ignores all existing and future resource loads that have occurred or will be occurring.

For a variety of reasons, some manufacturers prefer to schedule jobs according to the limitation of resources and in other situations they prefer to schedule outside the resource limitation.  Both infinite and backwards scheduling take into account material, labor, outside processes and child dependencies (in the case of assemblies) during the scheduling process.  The only part of the scheduling system that is finite or infinite is the labor resource portion and not the material.

MIE Trak has an advanced scheduling system which includes both finite and infinite scheduling.  MIE Trak is designed for most any type of job shop include made to order and engineer to order production organizations. You can visit the website at

http://www.mie-solutions.com

September 8, 2009 Posted by | Scheduling | , , , , , , , , , , , , , , , , , , | Leave a comment

What is Forward and Backward Scheduling

MIE Solutions offers a made to order job shop ERP system designed for the manufacturer of goods and products.  Most accounting systems are designed for the basic AR, AP and GL side of financials where a manufacturing software product deals with the actual production of the goods and services.   MIE Trak is a full featured ERP system for the made to order and engineer to order manufacturer.

What is scheduling?

Scheduling is a method where there is a set of x tasks which need to be completed on a set of y resources in an efficient manner.   Wikipedia gives us a good definition of scheduling “Companies use backward and forward scheduling to allocate plant and machinery resources, plan human resources, plan production processes and purchase materials.”

http://en.wikipedia.org/wiki/Scheduling_(production_processes)

What is forward scheduling?

Forward scheduling is taking a job with a number of tasks and allocates those tasks to resources as early as possible when resources the resources allow.   The first available time that the resource is available to be used the task should make use of it.   As with all scheduling methods there are pros and cons on how they work.   Forward scheduling may result in jobs being completed earlier then the requested due date because forward scheduling schedules the tasks as early as possible.   Forward scheduling tells you when a job could be completed vs completing the job when required.

What is backwards scheduling?

Backwards scheduling is taking a job with a number of tasks and allocates those tasks to resources in reverse orders and schedules the task on the resource.   Backwards scheduling requires a delivery date from the customer because the system schedules backwards from the delivery date to arrive at a start date.   Backward scheduling tells the manufacturer if this date could be hit based on the allocation of resources.   Unlike forward scheduling which schedules into the future, backward scheduling could potentially schedule into the past because the resources where not available to complete the job.   Backwards scheduling then may turn around and actually forward schedule the job to tell the customer the earliest delivery time.
Scheduling is very complex and this blog will try to go over many aspects of scheduling from types of scheduling, np complete problems, how to allocate resources, defining resources, etc.
Some of the benefits of scheduling include :
  • Process change-over reduction
  • Inventory reduction, leveling
  • Reduced scheduling effort
  • Increased production efficiency
  • Labor load leveling
  • Accurate delivery date quotes
  • Real time information
MIE Trak is a job shop software package designed to help manufacturers manage the work in their shop to the best of their ability.
http://www.mie-solutions.com

August 26, 2009 Posted by | Scheduling | , , , , , , , , , , , , , , | Leave a comment

What is a Job Shop Part 2

Welcome to the MIE Solutions Job Shop Scheduling blog. MIE Solutions ERP system provides a comprehensive job shop scheduling software to deal with the many problems scheduling a job shop encounters. Scheduling has become a critical factor in many job shops in order to determine their capacity for more work and be able to schedule their work more efficiently. Job shop scheduling becomes more and more difficult when you deal with assemblies and/or multiple components which need to be made in an efficient manner.

What type of work is done at a job shop?

The definition of a job shop can be broad or narrow depending on your situation. In this blog I’m going to define a job shop as a company which manufacturers both made-to-order parts and engineer-to-order custom products for a particular custom. Job shops can also by a hybrid of which makes custom products on a customer demand driven basis or they can have a product line in which they manufacturer, sell and/or distribute products which were made in house. Many manufacturers today began as job shops and grew into the other manufacturing processes as volume allowed. The job shop allows entrepreneurs the most flexibility in making a variety of products to meet customer quality and service standards.

Job shops include sheet metal shops, stamping houses, machine shops, wood working, plastics and many other industries which need parts manufactured. When we continue talking about scheduling we are not going to spend too much time on large product manufacturers, i.e. cars, trucks and other assembly line process. Assembly line processes need to be handled differently then most standard job shops.

The basic process a job shop uses to get a job to a customer is

RFQ is submitted to job shop

Job shop provides an estimating and quote to the buyer

Buyer awards the RFQ to the job shop

Job shop creates a sales order

Job shop creates a work order to produce the requirements

Work order is scheduled

Work Order is tracked and closed as the part is manufactured

Job is shipped to customer

As shown, there are a lot of steps a job goes through during a normal life cycle of a made-to-order part.    You can see that the scheduling is in the middle of the process, but is very critical in order to get the job out on time.

For more information visit

http://www.mie-solutions.com

August 19, 2009 Posted by | Scheduling, What Is A Job Shop | , , , , , , , , , , , | Leave a comment

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