What is a machine schedule?
A machine schedule is the central overview of which production orders are planned on which machine at which time. It forms the backbone of any organized production — from a small CNC job shop to a large industrial operation. Without such a plan, idle times, double bookings, and missed delivery dates arise.
At its core, a machine schedule consists of four building blocks that must work together:
Machine (Resource)
Each machine on your shop floor is an independent resource with its own capacity. Whether CNC mill, lathe, laser, or grinding machine — each resource has specific availability windows determined by shift models, maintenance intervals, and planned downtimes.
Time period (Shift window)
The planning horizon is determined by the configured shifts. A machine running a single shift has different capacities than equipment that runs around the clock in three shifts. The schedule must correctly reflect these differences per machine.
Order (Customer order)
Each production order has a workpiece, a required quantity, a material, and a delivery date. Often an order passes through multiple machines sequentially before the finished part is ready for shipment. This sequence must be reflected in the schedule.
Operation (Process step)
An operation is a single processing step within an order — for example “milling on the DMG MORI DMU 50” or “grinding on the Studer S31”. Only the sum of all operations, in the correct sequence assigned to the right machines, produces the complete schedule.
Traditionally, the machine schedule is maintained on paper, a whiteboard, or in an Excel spreadsheet. This works as long as the number of machines and orders remains manageable. Once companies grow, rush orders come in, and multiple employees plan simultaneously, this approach hits hard limits. This is exactly where software-based machine scheduling comes in.
Typical challenges in machine scheduling
Every manufacturing company knows these situations. The following problems occur particularly often when machine scheduling is done without suitable software:
Setup times are underestimated: When switching between different workpieces, fixtures, tools, and CNC programs need to be changed. These setup times add up significantly over the day. If you don't account for them in the schedule, you systematically create delays and overloaded machines.
Bottlenecks remain invisible: Often a single machine is the bottleneck of the entire production — such as the only 5-axis mill or the coordinate measuring machine for quality inspection. Without a visual display of occupancy, you only discover that this machine is overloaded when delivery dates have already been missed.
Short-notice rescheduling is chaotic: A machine breaks down, material is not delivered on time, an employee calls in sick. In such cases, the plan must be adjusted immediately. On paper or in Excel, this means: re-sort everything, manually check all dependencies, individually inform affected employees.
Rush orders blow up the schedule: A regular customer urgently needs parts. The rush order must be scheduled immediately — but where? Which running orders can be postponed without jeopardizing other delivery dates? Without an overview of the current occupancy of every machine, this decision is a shot in the dark.
No overview of the overall situation: The production manager switches between Excel spreadsheets, ERP lists, and phone calls with the shop floor. A single, up-to-date view of all machines, all orders, and all time periods doesn't exist. Decisions are made based on experience rather than real data.
Capacity gaps go unused: While one machine sits idle for two days, another order is waiting for exactly this type of machining. The gap was there, but nobody saw it. Unused machine time means lost revenue — and can be avoided through better transparency.
Methods of machine scheduling
In production planning, there are various strategies for assigning orders to machines. Each method has its strengths and is suited for specific situations:
FIFO — First In, First Out
The simplest rule: orders are processed in the sequence they were received. FIFO is fair to all customers and easy to follow. The downside: urgent orders with tight delivery dates must still wait, even when earlier orders have more buffer time. In practice, FIFO alone is rarely sufficient as a standalone strategy.
Shortest Processing Time first (SPT)
Orders with the shortest processing time are scheduled first. This increases throughput — many orders leave production quickly. However, you risk that large orders with long processing times keep getting pushed back and their delivery dates become at risk.
Earliest Due Date first (EDD)
The machine always processes the order next whose delivery date is closest. This method maximizes on-time delivery and is especially useful when delays have direct consequences — such as contractual penalties or line stoppage at the customer's plant.
Setup-optimized sequencing
Orders requiring similar tools, fixtures, or materials are scheduled back-to-back to minimize setup times. Especially with CNC machines that have long tool changes or elaborate clamping, this method yields significant time savings. The planner needs to know, however, which orders require similar setups.
Manual prioritization by the planner
In reality, machine scheduling can rarely be reduced to a single rule. Experienced production managers combine the strategies mentioned above and additionally consider factors like customer priority, material availability, and staffing levels. This requires a planning tool that gives the planner the overview to make quick, well-founded decisions.
GanttWork supports all strategies: The interactive planning board gives you full control. Sort orders by delivery date, group similar operations to reduce setup time, or move a rush order to the front of the queue via drag & drop. The visual display immediately shows what impact each decision has on the rest of the schedule.
Capacity planning under visual control
Capacity planning answers a seemingly simple question: Are my machines and shifts sufficient to complete all accepted orders on time? In practice, the answer is anything but simple, because it depends on dozens of variables — availabilities, dependencies, setup times, disruptions, and the daily influx of orders.
A Gantt chart makes this complexity manageable. Each machine is displayed as its own row, the time axis runs horizontally. The scheduled operations appear as colored bars — the longer the bar, the longer the planned processing time. At a glance, you can see:
Overloaded machines: Where bars pile up and orders need to be pushed far into the future.
Available capacity: Empty areas on the timeline show where machines are idle and new orders can fit.
At-risk delivery dates: Orders whose last operation extends past the delivery date are visually highlighted.
Uneven distribution: When three machines are overloaded while two sit idle, you see it immediately and can redistribute.
The decisive advantage over spreadsheets and lists: the human eye perceives graphical patterns in fractions of a second. A gap in the schedule, a bottleneck at a machine, an order that extends past its delivery date — all of this jumps out on the Gantt planning board, while it easily gets lost in a spreadsheet of numbers. Visual capacity planning is therefore not merely more comfortable, but actually more precise and faster.
How machine scheduling works with GanttWork
GanttWork was specifically developed for manufacturing companies that need to plan and adjust their machine scheduling on a daily basis. The following six core features make the difference:
Drag & drop onto the machine
Each operation is displayed as a bar on the planning board. Via drag & drop, you move operations along the timeline or between machines. Place the milling job on your DMG MORI instead of the Hermle by simply dragging the bar into the desired machine row. The planning board automatically checks whether the selected time slot is available and shows conflicts immediately.
Automatic cascading
An order with four operations (e.g. sawing → milling → turning → finishing) forms a chain. If you shift the first operation by two days, all subsequent operations automatically move along — maintaining the planned sequence and without overlaps. This saves manual replanning and prevents logical errors where a later operation starts before an earlier one.
Shift calendar per machine
Configure an individual shift model for each machine. The mill runs on two shifts, the laser only during the day, the EDM machine around the clock. GanttWork takes these differences into account when calculating processing durations and schedules operations exclusively within available shift windows. Weekends, holidays, and planned maintenance periods are automatically skipped.
Real-time feedback from operators
A worker terminal can be placed at every machine — a tablet, a touch monitor, or a simple PC. The machine operator sees their current job with all relevant information and reports work progress in real time. The planning board updates immediately: completed operations are marked green, active jobs are highlighted blue, and delays are flagged red. This way, the plan matches reality — not just theory.
Insert rush orders with precision
An urgent order comes in and needs to go on the machine immediately. In GanttWork, you simply drag the rush order to the desired position. Through automatic cascading, all subsequent orders on this machine are shifted accordingly. You see in real time which delivery dates are affected and can immediately take corrective action — for example, by moving a less urgent order to an alternative machine.
Utilization overview and planned vs. actual comparison
GanttWork shows you not only the current plan but also historical performance. The planned vs. actual comparison compares planned processing times with actually measured times. This reveals systematic deviations — for example, that milling a specific workpiece always takes 30 percent longer than estimated. These insights feed back into more precise planning times, more accurate quotes, and more realistic machine scheduling.
Case study: CNC shop with 10 machines
A mid-sized CNC job shop in Upper Austria operates ten machines: four CNC mills (3-axis and 5-axis), three CNC lathes, a saw, a surface grinder, and a manual measuring station for quality inspection. The shop handles around 60 open orders simultaneously with over 200 operations combined.
Before GanttWork: The production manager planned with a large Excel spreadsheet and a whiteboard on the shop floor. New orders were scheduled by gut feeling. When a rush order came in, the entire plan had to be manually rebuilt — often taking an hour alone. On-time delivery was around 72 percent, because bottlenecks at the 5-axis mill were regularly discovered too late.
With GanttWork: All ten machines are set up as resources on the planning board, each with the appropriate shift model. New orders are imported via Excel and operations are distributed to machines via drag & drop. The production manager sees at a glance that the 5-axis mill is fully booked three weeks ahead and schedules new orders specifically to the 3-axis mills or evaluates whether a night shift would be economically worthwhile.
Results after three months
The real-time feedback via worker terminals was particularly valued: the production manager sees from his office which order is currently running on which machine, how far processing has progressed, and whether the plan is being met. For customer inquiries about delivery status, a glance at the planning board suffices — instead of a walk through the entire shop floor.
Plan your machine scheduling better, simply
See for yourself how GanttWork makes your machine scheduling more transparent, faster, and more reliable. We'll set up a dedicated demo instance for you — with your machines, your shift models, and real order data on request.
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