Do You Really Need to Save Seconds in Scheduling? YES! Want to know how to translate a second into dollars? It all comes down to calculating your scheduling down to the second. Many applications don’t even use minutes to compute schedules. They use time “buckets” of five- or 15-minute intervals–or even hours or days. You’ll see this “buckets of time” approach most commonly in spreadsheet-type scheduling applications because each column in a spreadsheet can be used to represent an interval of time. But, as I’ve written in a previous blog, (Click here), time buckets provide computational conveniences for the application[...]
The Evolution of Scheduling If you’ve ever watched Jimmy Fallon do any of his Evolution of Dance bits, you’ll notice a couple things: We Americans started out simple, moving our bodies out of necessity with a basic step-touch, then curiously to more complex moves to accommodate more complicated beats (hello, Break Dancing), and we’ve ultimately swung back to a more simplified—albeit more “sophisticated” set of moves. All this is a long-winded, yet very applicable way of illustrating the evolution of scheduling applications as well, believe it or not. The construction business was the genesis of project scheduling and it’s easy[...]
The Pillars of Success (and Making the Case for Having an ATP Calculator Handy) If the old proverb “Necessity is the mother of invention,” then surely the need to provide accurate promise dates is the mother of finite capacity scheduling. It’s absolutely true. Let’s start with the basics: Any good business analyst will tell you that success often rests on these three pillars: A quality product; A fair price; and Delivering that product on time. For many businesses, that last one–delivering your product on time–is often the toughest piece to achieve and a principle reason for failure. Because your business[...]
The ABCs of Scheduling: A Return to the Basics: Previously, in this BLOG, we have discussed the subtleties of various scheduling applications. A good app must accommodate many capabilities—some obvious, some not-so-obvious. That said, let’s review the basic capabilities that should be at the heart of any scheduling app. These are the core features that form the framework onto which detailed capabilities can be attached. Let’s take it from the top: A: Activities should be objects of scheduling, not resources. It’s a mistake to think of scheduling resources because inevitably you will wind up looking for times when several resources are needed at the same time.[...]
Flexible and Accommodating: Can Your Scheduler Do That? It’s all very simple when you explain your manufacturing process to your mother/neighbor/in-laws, right? And it is–normally. You manufacture widgets. Normally, a widget run produces two dozen widgets. The five-step process goes something like this: Set-up the widget-making machines Perform step A Perform step B Perform step C Take-down and clean the machines This process, or “routing,” is a sequential process, of course where each step follows the previous. Scheduling this sequence is not much of a problem for most scheduling applications. However, it gets more interesting (code word for “complicated”) when[...]
May The Force Be with You! The question here is a good one: How do you make the impossible, possible? Recently, a product producer wanted the capability to “force” a production sequence onto an already heavily-loaded schedule. This request was motivated by the desire to satisfy his customer’s delivery date despite the fact that his scheduler said the product couldn’t be produced by the desired date. The ‘force on’ capability raises the question of how constraints are handled within the scheduling logic. For many years, constraints were approximated by using average lead times. In effect, this is infinite capacity scheduling. Capacity[...]
Decision Support Versus Decision-Making: A Trap for Schedulers We all love automation. How can we not? Our coffee makers brew our morning joe at the exact temperature we prefer each morning, we have a customized news feed in the palm of our hands to bring us only the genres of news we like to see—in fact, we have nearly every daily function we perform for ourselves and others within a few clicks. Boom! We love it. The evolution of scheduling is no different. For at least 30 years, schedulers have recognized the need computers and automation. Even for moderately-sized operations,[...]
Scheduling Is Not Your Problem–Rescheduling Is! What takes longer: building a schedule or revising a schedule?? Most operations analysts believe revising a schedule takes more time.. But why? The answer is that things seldom go as planned. Feeding the actual circumstances back into the planning process necessitates replanning. This feedback loop is apparently ignored by some of the scheduling tool designers. When you think about it, the replaning process is like a control loop where the errors must be compensated and damped out in a stable manner. Fixing these “errors”, which are the difference between the planned vs the actual,[...]
Confessions of an Optimizer: When is “excellent” good enough? As we all know, an optimal solution is best when it comes to any scheduling operation. But is optimal always practical? Not necessarily. If you have an environment with frequently changing requirements like most operational situations, you may need to shoot for “excellent” rather than “optimal.” Optimizing a schedule involves a search for alternative resources to use and the times to use them. But there are a lot of constraints that must be satisfied. The resources have limited availability and when they are available, they are available in limited quantities. Start[...]
Challenges Accepted: What Are Yours? Here are 10 real world scenarios I’ve encountered recently that require some serious know-how in order to set up a scheduling application. (Of course, the application itself must have the descriptive and solution capabilities to handle the complex scenarios.) Perhaps you can relate to something in this list. Some of my activities are a week long. Those must always start on a Monday. My presses run long jobs but the paper trays must be reloaded periodically. It takes an attendant about 10 minutes every hour to do this reload, but the presses should not be[...]