Finite Capacity Scheduling Software As a Strategic Weapon
Do you view shop floor scheduling simply as a way to order the next jobs into machines on your shop floor? If so, you may be leaving money on the table. The same technology that allows you to schedule your shop floor can give you unprecedented visibility into your operations. You can use this technology as a strategic weapon to transform your business.
Work is getting done on your shop floor. This work is dispatched to machines and people in a particular order. Therefore, regardless of the tool (or lack thereof) that you are using, you are currently scheduling your shop floor.
We’ve seen a wide range of tools used to schedule. We’ve seen people use manual tools such as handwritten scraps of paper, lists on whiteboards, and magnetic Gantt charts. We’ve also seen people employ software based tools such as ERP, spreadsheets, and project management software.
All of the tools discussed above, manual or automated, help you create an ordered list of what to run next on the shop floor. However, scraps of paper or list on a white board obviously don’t accurately reflect the reality of your shop floor. Quite frankly, computerized tools such as ERP aren’t much better since they don’t consider the real capabilities of your operation. None of the tools discussed above give you an accurate model of your shop floor operations.
Finite capacity scheduling software (also known as advanced planning and scheduling software) allows you to create an accurate model of your manufacturing operations, and allows you to develop detailed sequence lists (schedules) for the shop floor. Finite capacity scheduling software starts with accurately modeling your constraining resources. Examples of constraining resources handled by finite capacity scheduling software include machines, labor, and tooling. Advanced planning and scheduling software additionally handles constraining material. Constraining resources have availability – for instance, you may have different quantities of labor available different shifts, machines may be broken down, tools may be out for preventative maintenance, and material my fully allocated.
Finite capacity scheduling software / advanced planning and scheduling software then incorporates the demand for those resources. For instance, an order for a product may go through multiple steps. Each of these steps ties up (or consumes) one or more constraining resources for a period of time. Multiple operations of multiple orders can compete for the same resources (for example, multiple operations scheduled on a machine). When a resource is tied up (consumed), finite capacity scheduling software \ advanced planning and scheduling software will schedule operations forward or backward in time, considering the availability of the resource. The output of the process is detailed, accurate start and finish times for operations and for orders.
A detailed dispatch list (or schedule) can be created based on operation start and stop times. This detailed dispatch list can be provided to operations staff, and gives them direction on what operations should be run in what sequence on the shop floor. However, these schedules are just a small part of the benefits that the technology provides.
The same finite capacity model that you can use for detailed scheduling can be used to help you make better business decisions. The model gives you visibility into when work will finish. As the software extends detailed schedules out in time, it accurately predicts when customer requirements will be available, and allows you to make promises to customers that you can keep. Good finite capacity scheduling software \ advanced planning and scheduling software also will provide a wide range of different analysis tools. These tools should give you the ability to generate unlimited what-if scenarios, and to compare these scenarios against key business metrics. Examples of what-if scenarios that you might try are grouped into categories below:
- Problems with capacity – breakdowns, quality problems, material loss / shortage, lack of people
- Changes in demand – more orders, change in order priority / quantity / due date, drop in orders
- Changes in the capacity – overtime, alternate routings (including outsourcing), off load, change sequence / expedite, reduce quantities / split orders, new equipment, change staffing
Performing the analysis described above will help you make significantly better business decisions. Consistently making better business decisions can give you a huge advantage over your competition. You can use finite capacity scheduling software and advanced planning and scheduling software, viewed by some as only a way to generate short term machine sequences, as strategic weapons to transform your business.
Advanced Planning and Scheduling Software for Engineer to Order Businesses
We define an engineer to order (ETO) business as one that creates a unique product to a customer’s specification. Examples of those unique products range from complicated electronics or machinery with thousands of parts, to much more simple items such as printing or packaging.
If you run an ETO business, regardless of your product complexity, you know that managing customer’s delivery expectations is critical to your success. Customers order unique product to fit a specific business need. Therefore, it only stands to reason that they are very concerned with when that product will be available. Often customers not only expect you to make and keep delivery promises, but also want you to report progress against important engineering and manufacturing milestones.
The key to promising delivery is future visibility into when customer orders will finish. Software that provides this visibility must schedule in a manner that explicitly considers constraints, and schedule work out in time based on real capacity.
Furthermore, good customer commitments in ETO environments need to consider both engineering and manufacturing. Tasks in either of these areas can take longer than expected, delaying overall delivery to customers. Lack of commonality between engineering and manufacturing complicates the situation. Time in engineering can be influenced by the amount of engineering required, and scarce, highly skilled engineering resources. Time in manufacturing can be influenced by a host of factors such as limits on machines, tooling, and material, as well as skilled manufacturing labor. Manufacturers have historically turned to two disparate tools to help; Project Management Software which helps plan engineering, and ERP Software which helps plan manufacturing.
Project Management Software allows engineering projects to be broken into an almost unlimited number of tasks, with complicated relationships (dependencies) between the tasks. There is some debate as to how well Project Management Software handles a single finite constraint (typically it uses a post schedule “leveling algorithm”). However, Project Management Software has little or no capability to handle the multiple finite constraints that occur in manufacturing. Project management software also is not designed for the intricacies of manufacturing environments. For instance, Project Management Software doesn’t do a good job of handling large volumes of orders. It also is not designed to handle alternate resources, automatic splitting of operations, batch machines (ovens), time per piece calculations, sequence dependent set up times, bills of material, etc.
While more suited to manufacturing environments, ERP Software also has serious deficiencies when scheduling. ERP Software traditionally schedules \ plans in a backward infinite manner, considering estimated lead times rather than real production constraints. ERP Software is also notoriously weak when considering the complicated task dependencies that occur in engineering. ERP’s lack of flexibility in handling task dependencies also impacts its ability to effectively handle ETO manufacturing. For example, rather than modeling complicated operation relationships (e.g. a top and bottom of a tool being processed in parallel) directly, ERP forces these relationships to be specified with bills of material.
Advanced Planning and Scheduling Software gives you the best of both worlds. Like Project Management Software, Advanced Planning and Scheduling Software can model the complicated task dependencies that occur in both ETO engineering and manufacturing. Like ERP Software, Advanced Planning and Scheduling Software can handle large volumes of orders, bills of material, and time per piece calculations. Advanced Planning and Scheduling Software also has the capability to address manufacturing complexities such as alternate resources, automatic splitting of operations, batch machines (ovens), and sequence dependent set up times.
Most importantly Advanced Planning and Scheduling Software can accurately model and schedule all constraints (e.g. machines, tooling, material, engineering and manufacturing skills) in a finite manner. Advanced Planning and Scheduling Software’s finite scheduling features give you the future visibility you require. Advanced Planning and Scheduling Software helps you make and keep customer delivery promises. Advanced Planning and Scheduling Software also allows you to report to your customers’ progress against important engineering and manufacturing milestones.
Should Your Production Scheduling Software Consider Tooling?
You are evaluating production scheduling software. Should the ability to automatically consider tooling be a requirement? If so, how?
The need for your production scheduling software to consider tooling constraints is very much dependent upon your type of business. Some businesses don’t need tooling to be considered at all. In other businesses, the way in which tooling should be handled by the production scheduling software is very much a function of the type of business. Some different types of tooling that might be used by different kinds of businesses are described below:
1. Consumable tooling – an example might be a cutting tool. These types of tooling wear down as they are used. Eventually, the useful life of the tooling is exceeded, and it is discarded. Consumable tooling is usually fairly inexpensive.
2. Fixed Tooling – examples might be injection molds in the plastics industry or progressive dies in the stamping industry. Usually this tooling is quite expensive. In some cases, fixed tooling can produce more than one part simultaneously. The simultaneously made parts may be the same or different part numbers. In other cases, fixed tooling can produce different part numbers only after tooling components are changed out. Sometimes fixed tooling can only run in a subset of available machines (e.g. a mold may run in an injection machine of 50 tons, but not an injection machine of 25 tons).
3. Tooling components – per number 2 above, changing tooling components in mold or a die can result in the mold or die producing different part numbers.
Fixtures – fixtures are similar to fixed tooling in that they can be quite expensive.
4. Fixtures – differ from fixed tooling in that fixed tooling is typically used at one operation. However, a part can be attached to a fixture and travel with it through multiple operations.
What kind of features should your production scheduling software have to handle the types of tooling discussed above?
1. Consumable tooling – Must handle the gradual consumption of the useful life of the tool. Often modeled as inventory. Each individual tool is modeled as an inventory location. The life of the tool is the quantity of inventory available in the location. The quantity required on the operation’s bill of material is the life of the tool required at that particular operation.
2. Fixed Tooling – Should allow more than one but less than an infinite number of parts to be scheduled from the tool simultaneously. Must allow only certain part numbers with certain characteristics to be scheduled simultaneously in the tool. Should conditionally pick tools and machines so that feasible solutions are chosen – e.g. a mold requiring 25 tons of pressure can run in either 25 or 50 ton machines, but a mold requiring 50 tons of pressure can only run in 50 ton machines.
3. Tooling components – Must be modeled concurrently with the main tool (mold or die). The software needs to schedule so feasible combinations of main tools, components, and machines are chosen.
4. Fixtures – The software needs to schedule so that if a fixture is used over multiple operations, the fixture must always be tied up, even for the time the associated part is waiting in queue.
Make sure that the production scheduling software you chose has the necessary features to model the types of tooling that are important in your business.
Should Your Production Scheduling Software Consider Labor?
You are evaluating production scheduling software. Should the ability to automatically consider labor constraints be a requirement?
In the vast majority of cases, emphatically yes! About the only exception is if every pieces of equipment in your facility is fully staffed for every shift you are operating, all the time.
In most manufacturing environments, even those that are nominally fully staffed, full staffing is not a 100% certainty. Change is a fact of life. “Hot” orders hit, you need to add weekend overtime, and not all staff members are able to work. People call off sick. You may have trouble keeping less desirable shifts (evening and graveyard) fully staffed.
Why is considering labor constraints (and associated skill levels) important? Labor constraints are a key component of your capacity. If you consider labor infinite, you could significantly overstate your capacity. If your available capacity is not properly considered, you will lose the predictive capability of production scheduling and advanced planning and scheduling software. The software will generate estimated completion dates sooner than you can realistically meet. You could create significant customer service problems if you promise delivery to your customer based on these overly optimistic dates.
A common situation is when you have your first shift fully staffed, a partial second shift, and a skeleton third shift. Assume there are ten pieces of production equipment in an area of your plant. Assume staffing levels on first, second and third shift of ten, five and two people respectively, and a staffing requirement of one person per machine. At the end of first shift, five pieces of equipment will need to be shut off due to lack of staff, and at the end of second shift an additional two pieces of equipment will need to be shut off.
It can be quite difficult and time consuming to shut off pieces of equipment manually to reflect labor shortages and job importance. You would need to not only shut off equipment today, but for the duration of your scheduling horizon. The task will quickly become unmanageable if you have more than a handful of pieces of equipment and a scheduling horizon of more than a few days. However, good production scheduling software will handle this task automatically, and keep the most important jobs running by assigning labor based on job importance (e.g. due date, priority, etc.).
Why Do You Need APS Software to Explode Bills of Material?
You have an ERP System that performs bill of material explosions. Your interface can easily pass exploded orders to your Advanced Planning and Scheduling system for production scheduling. Why then might you want to consider exploding bills of material in your Advanced Planning and Scheduling Software (APS)?
If you make strictly to stock, or if you have very flats bills, you probably don’t need APS’s bill of material explosion capability. However, if your bills are more than two levels deep, Advanced Planning and Scheduling’s bill of material explosion and CTP (Capable-to-Promise) features can dramatically improve the accuracy of delivery dates that you promise to your customers, and the speed at which you provide those dates.
Given its architecture and the fact that it considers all of your items, the explosion of bills in ERP is typically a long process. In some ERP environments, the process is scheduled to occur overnight. To speed up the process of quoting delivery to customers, ERP systems have come up with an approached called ATP (Available-to-Promise).
ATP simply allocates available inventory against the top level (or Master Production Schedule) item being promised. If inventory isn’t on-hand, ATP assumes that inventory will be available based on some aggregate lead time. ATP doesn’t consider the availability of capacity, and it doesn’t typically consider the availability of lower level components.
Since it considers only rough estimates of lead time, promise dates from ATP can be wildly inaccurate. These bad promise dates can hurt customer relationships and / or throw your plant into turmoil as you strive to meet unrealistic dates. Companies often carry excessive inventory to buffer against inaccurate ATP estimates, driving up costs.
Contrast ATP with CTP (Capable-to-Promise), a set of features in most good APS systems. When generating detailed, accurate promise dates, CTP considers the finite capacity of your limiting resources such as machines, tooling, and labor skills. CTP also considers limited on-hand and on-order material. The availability of on-order material is based on the scheduled receipt dates of both purchase orders and finitely scheduled component manufacturing orders. CTP will take orders from ERP, but then explode only material related to the item being promised, so it generates promises very quickly.
A good CTP system, also:
- Highlights available dates that will not meet customer requests.
- Identifies bottleneck constraints (e.g. missing or delayed component items) that are causing late fulfillment.
- Shows exactly how existing inventory is allocated to higher bill levels and to customer requirements.
- Supports what-if rescheduling with dynamic pegging which re-allocates inventory and projected receipts to show the impact of changing customer priorities or requirements.
- Allows unlimited scenario generation and the ability to compare what-if scenarios on different metrics (e.g. on time delivery, order days early / days late).
Exploding bills of material in an APS (advanced planning and scheduling) system with CTP (capable-to-promise) features can help you more accurately promise inventory to customers, resulting in better customer service, less operational turmoil, lower inventory, and increased profitability.
Managing Advanced Planning and Scheduling Software Risks (Part 2)
In a previous post we started discussing the risks associated with implementing production scheduling, production planning, or Advanced Planning and Scheduling software, and how to manage those risks. We continue the discussion below.
5. Poor Implementation Project Management
Depending upon your goals, and your starting point, implementation of Advanced Planning and Scheduling at your company might require significant time and resources. The longer and more complex your implementation, the more crucial is a good implementation project plan, and the management skills to keep the project on track.
A reputable vendor should help you develop a customize implementation plan based on their experience with other customers. Waterloo Manufacturing Software has done hundreds of implementations over the past twenty years. You can read about some of the common steps in our implementation methodology at Implementing Advanced Planning and Scheduling Software.
6. Problems Integrating Advanced Planning and Scheduling Software with Existing Data Bases
Although some customers will implement planning and scheduling software in a stand-alone manner, the majority of companies will integrate the software with existing data bases and legacy systems. Since the production scheduling software is then dependent upon data maintained in other systems, integration problems can delay or even derail your implementation.
When integrating, at least some help from your information systems group can be extremely valuable. Securing the assistance of busy information systems staff, and working with them efficiently, can be challenging. You can view suggestions for integrating advanced planning and scheduling software, and see suggestions for the best way to work with your information systems group, at Integrating Advanced Planning and Scheduling Software.
7. Lack of Staff “Buy In”
The single most important factor in the success of your Advanced Planning and Scheduling software implementation is the support of your planning and scheduling staff. You’ll need their expertise to help with the software implementation. However they are usually the same people you’ll also depend upon to keep your plant running on a day to day basis using existing methods during the implementation.
Once implemented, the software should relieve existing staff of repetitive work, and allow them to use their talents in more creative ways. However, in the short term, their work load will increase. To get their buy in and support, it is important that you realistically describe how the content of their jobs will change during and post implementation. You can read more about how to secure staff support at How do I Get “Buy In” for My Advanced Planning and Scheduling Software Implementation.
8. Insufficient Staff Skill Levels
You shouldn’t buy Advanced Planning and Scheduling software simply to automate existing scheduling methods, but rather to harness the power of the software to fundamentally change the way your organization plans and schedules. Therefore, the jobs of planning and scheduling practitioners should change during and after implementation.
Managing Advanced Planning and Scheduling Software Risks (Part 1)
You are planning to purchase production scheduling, production planning or Advanced Planning and Scheduling (APS) software. You’ve done your homework, and done a justification. The software should more than pay for itself. However, you know that there is risk in any software implementation. How do you identify the risks and how to manage them? This post seeks to help. It lists below some of the more common risks and suggests mitigation strategies:
1. Unclear Goals
As discussed in What Problem are We Trying to Solve?, everything about your Advanced Planning and Scheduling Software project flows from your goals. Your goals will drive how your scheduling model is built, how you interact with your production scheduling software vendor or vendors, and what software you decide to purchase. If your goals are not clearly agreed upon, stated, and communicated, you will chase your tail.
2. Lack of features
You’ll need robust production scheduling / production planning software to help you reach your goals. How can you be sure the software you are evaluating can help? We advocate working with your vendors to build a sample scheduling model. This model should be targeted at your goals, reflect your manufacturing environment, and include samples of your data. Read more about the software demo at How Do I Know if A Production Scheduling Solution Can Solve My Problems?
3. Poor vendor relationship
Work together with prospective advanced planning and scheduling software vendors prior to the sale to know what they will be like to work with after the sale. The best forum for this work is the sample scheduling model discussed above. After going through the process of building this model, you will learn much about your vendor. You can learn more about picking a vendor and checking vendor references in How Should You Pick a Production Scheduling Vendor? and How Should You Use Production Scheduling Vendor References?
4. Bad or Incomplete data
In order to generate good schedules, Advanced Planning and Scheduling software can require more detailed and accurate data than your organization has. To some extent, poor or incomplete data in will equal poor schedules out. To mitigate this risk, work with your vendor to develop a data plan before you purchase. It can also be helpful to select software that allows you to generate reasonable schedules with minimal data, and allows you to refine those schedules over time as you collect more detailed data. You can read more at How Can I Satisfy the Data Needs of Production Planning and Scheduling Software?
In the next post, look for more risks associated with implementing production scheduling and production planning software, and learn about how to manage those risks.
Integrating Advanced Planning and Scheduling Software (Part 2)
In a previous post we started discussing the integration of production scheduling, production planning, or Advanced Planning and Scheduling software with your existing data bases and legacy software applications. We continue the discussion below.
Prepare Your Information Systems Group for Some Programming
Prospective customers often assume that data can simply be transferred directly from their existing systems to the planning and scheduling software. This is rarely the case 100% of the time, despite the fact that the software world has made amazing strides in connectivity between data bases.
Programming logic is typically built into the interface to manipulate or augment data as it is transferred between other data bases and the scheduling software. The manipulation is required because the systems involved might not hold data in the same formats. The augmentation is required because typically the production scheduling software requires more detailed data than may available in the customer’s other data bases.
An example of the manipulation data is the case of a customer who wants to group like work together to minimize set up. This customer uses “smart” part numbers, and among other characters, a portion of the part number holds data that identifies the part as being part of a part family. In this case the interface strips the part family data from the larger character string and writes the part family data in a field the scheduling software uses for minimizing set up.
An example of the augmentation of data is case of a customer that sometimes moves product between work centers in less than full order quantity (between machining operations) and in other cases moves product in full order quantity (after heat treat). The customer’s business system does not hold data that describes the relationships between operations. In this case, the interface checks the work center of the sending operation and, based on this work center, writes the appropriate relationship (overlap or sequential) to the proper field in the scheduling software.
Provide Your Information Systems Group Detailed Specifications
As keepers of technology that can greatly increase organizational efficiency, the time of your information systems group is always in high demand. Be respectful of their time. We’ve found that information systems groups do not react well to open ended, poorly thought through requests. We’ve found the best way to interact with information systems groups is through well thought out, detailed specifications. We strongly recommend that you and your Advanced Planning and Scheduling software vendor provide your information systems group with a detailed specification on the interface between other company data bases and your production planning and scheduling software.
Integrating Advanced Planning and Scheduling Software (Part 1)
You’ve just purchased, or are about to purchase production scheduling, production planning, or Advanced Planning and Scheduling software. How should you go about integrating your new software with existing data bases and legacy software applications?
Rely on Your Vendor for an Initial Data Plan
As part of the sales process, your planning and scheduling software vendor should have worked with you to create a demonstration model using samples of your data. The vendor should have used this sample model to show how you would use the planning and scheduling software to reach your goals. As your vendor puts together the demonstration model, he or she should have become familiar enough with your organization’s data to create a Data Plan for you.
The Data Plan will show data flows into and out of the planning and scheduling software. Most often, there will be two categories of flows into the software, data typed in manually, and data transferred electronically through an interface. This post concentrates on data transferred electronically, which will typically be data that either changes frequently, and / or data the software needs in large volumes.
Get Your Information Systems Group Involved
Your Advanced Planning and Scheduling vendor wants you to be successful with their software. If your organization doesn’t have the information systems resources available to manage the electronic transfer of information, most vendors will create the interfaces for you.
However, even if the vendor executes the transfer, your information systems group’s help can still be very valuable. Regardless of who develops the interface, they will need knowledge of how your data files are structured and where particular data elements are located. While a vendor building the interface can usually figure out what they need to know, guidance from your information systems group can ensure the vendors can find necessary data most rapidly and efficiently.
Since the help of your Information Systems Group is important regardless of who builds the interface, get them involved relatively early in the process. First, they will appreciate your advising them of the project and their potential role in it so that they can plan appropriately. Second, their insight into data availability can help your vendor as the vendor builds the demo model and creates the Data Plan.
In the next post, look for more advice on integrating planning and scheduling software.
How do I Get “Buy In” for My Advanced Planning and Scheduling Software Implementation?
You are considering implementing Advanced Planning and Scheduling software. You know that the “buy-in” of your people is crucial to the success of your implementation. How should you set proper expectations? What should you do to get your people on board?
Involve Them in Targeted Demonstrations
Elsewhere on this site, we advocate working with your vendors to build and demonstrate a sample scheduling model. This model and demonstration should be reflect your manufacturing environment, include samples of your data, and show in a detailed manner how the production planning and scheduling software can be used to achieve your goals. Operational and planning and scheduling staff should be involved in this demonstration. It will focus your staff on the benefit the software can bring to your company. The demo will let them see the proverbial pot of gold at the end of the rainbow.
Help Planning and Scheduling Staff Understand How the Content of their Jobs Might Change
You will not get the full benefit of production scheduling software or production planning software through simply automating existing manual processes. Therefore, change is inevitable. When change is afoot, it is natural for staff members to question how that change will affect each of them personally. Setting realistic expectations will allay fears and increase buy in.
The goal when implementing any business software system is to marry what software does well with what people do well. In the case of planning and scheduling, software can perform the repetitive tasks associated with building a scheduling much faster than any person. Software can also present schedule output in easy to interpret formats. People are best at analyzing software output in light of their knowledge of business conditions, and in using their creativity to use the software in ways that solve real business problems.
The net result of the software on staff time may be a “wash”. The software will generate schedules much more quickly than ever before. However, to achieve full benefit from the software, staff may need to devote the time saved on repetitive calculations to increased analysis. This increased analysis is what drives business benefits.
Plan for a Heavier Work Load During Implementation, and Look for Creative Ways to Manage the Extra Work
Advanced Planning and Scheduling software Implementations can take some time. The implementation will require the input of existing planning and scheduling staff. For instance, staff will need to describe important information that productions schedules require, and review trial software-generated production schedules for “goodness”.
However, in addition to helping with the implementation, planning and scheduling staff need to keep the existing business running and hitting its targets. You should try to maintain morale by looking for ways to lighten their load. For instance, temporary staff might be able to assume more repetitive calculation or data entry tasks. Also, rather than increasing the load of existing planning and scheduling staff, you may want to involve in the implementation staff with specific expertise in project management.
Ask Shop Floor Staff for Their Help
As a key internal customer for the output of the manufacturing scheduling software, shop floor staff need to be involved. Their opinion on what constitutes a “good schedule” can be as important as that of planning and scheduling staff. They also need to be prepared for schedules that are, at least initially, different from what they are used to. Schedules will improve as the organization becomes more familiar with the planning and scheduling software and the revised planning and scheduling process. Shop Floor staff need to understand that their input and patience are crucial to the success of this process.
Provide Proper Training
Most managers realize that basic training (on “which buttons to press when”) is essential to the success of any software implementation. While such basic training is also required for the success of Advanced Planning and Scheduling software, you’ll probably need to provide your staff additional training to broaden the scope of their business skills.
You’ll achieve the most significant benefits from planning and scheduling software when you use it as a decision support tool. Used in this manner, the software can show you the impact of alternate business decisions both in the present and in the future. Existing staff often need training to understand what alternative business decision to test in what circumstances, and how to evaluate and chose the best scenario when business metrics are in conflict. You can read more about Training for Advanced Planning and Scheduling Software.