Production counter system with button press, featuring a comparison display of actual production figures at 7 stations for Thai manufacturing plants

How the brief came about

The goal in this case was to see each station's plan against actual count during the shift, rather than waiting for figures from a count at the end. The scope of work agreed with the customer required the system to run offline, meaning it works on its own on a machine on the line without connecting to an external network.

Because each model takes a different time to produce, the plan for each time slot changes with the model being produced. The customer therefore wanted a system that calculates the plan according to the model and shows results separately for day and night shifts.

Requirements and constraints

The system must count output with push buttons at the workstations and must work on the line's internal network. The main requirements and constraints are as follows.

• Count actual output with a Hand Switch button that the operator presses when each piece is finished, covering 7 workstations
• Calculate the plan from the Cycle Time of the model being produced, and show the time, plan, actual count and difference for each time slot
• Separate day and night shifts, with up to 10 time slots per shift
• A summary page of totals across all stations for supervisors
• Run on the internal network, on 1 Server machine on the line, without needing internet access
• On-site installation is outside our scope

How the system calculates the plan and counts actual output at each station

The Station Dashboard display at each station counts down according to the Cycle Time of the model being produced. Each time a cycle completes, the plan increases by one piece. The actual count increases each time the operator presses the Hand Switch button. The system can therefore calculate the difference for each time slot immediately, and nobody has to work out the plan by hand when the model changes.

We chose to calculate the plan from Cycle Time because this line produces several models with different times per piece. When the model or working time changes, the administrator edits the CSV file and uploads it through nimitFlow Lite. The workflow is as follows.

1. 1

   Set models and working time slots

   The administrator enters the line name, model names, the Cycle Time of each model and the stations in use into a CSV file, sets the working time slots for the day and night shifts, then uploads it through nimitFlow Lite to send the values to all stations.

2. 2

   Station display calculates the plan

   When a working time slot begins, the Station Dashboard display counts down according to the Cycle Time of the model being produced. Each time a cycle completes, the plan increases by one piece and a new cycle count begins.

3. 3

   Operator presses the button when a piece is finished

   Each time one piece is finished, the operator presses the Hand Switch button. The actual count on the display increases, and the system immediately calculates the difference against the plan for that time slot.

4. 4

   View the time-slot table at the machine

   Each station's display shows the model name, line name, Cycle Time, the station's enabled/disabled status (Online/Offline) and a table of time, plan, actual count and difference for each time slot in the shift.

5. 5

   Summarise totals on the Server Dashboard

   The supervisor selects a date to view the total plan, actual count and difference across all stations by line and model, and selects a model to view a graph of each station's production output by time slot. The view can be switched between day and night shifts.

Deliverables

We delivered the production count system software with 7 sets of processing boards. This work took about 2 months, from August to September 2024.

• Station Dashboard for 7 stations: display of plan, actual count and difference, with a time-slot table for each station
• 1 Server Dashboard set: a Web Application (a program viewed through a web browser) with an SQL database (a system that stores data in tables) on a Server machine on the line, summarising totals by line and model, with time-slot graphs
• Configuration through nimitFlow Lite: CSV files for models, Cycle Time, stations in use and working time slots
• Processing boards (Embedded Processor) with power adapters, 7 sets for 7 workstations
• Testing against the acceptance checklist (Exit Criteria)

Results confirmed from the delivery documents

The confirmed results of this case are the delivery and the testing as documented. We delivered the full 7 sets of processing boards with power adapters in August 2024 and tested the system against the acceptance checklist, covering the configuration, Station Dashboard and Server Dashboard parts, in September 2024.

User manual version 1.0 was prepared in October 2024. The delivered system is designed so that supervisors can see actual count against plan for each station during the shift. This case has no production performance figures from after use began, so we report only results backed by documents.

What we learned

This work offers principles for production count systems and line-side plan vs actual displays.

• The plan on the display is only as reliable as its input data. When the plan is calculated from Cycle Time, the model table, Cycle Time and working time slots of each shift must match actual site conditions before use begins. If these figures are wrong, the difference on the display will be wrong too.
• Model changes need an agreed procedure. This system does not clear counts already recorded when settings change, so the administrator should update the configuration before a working time slot starts and reopen the program at the station, so that counts from the old and new configurations do not mix.
• The scope of installation work must be clear from the start. When on-site installation is out of scope, who prepares the board power supply and the Wi-Fi signal at each station must be agreed in advance, because every station must be able to send data to the Server machine.

How can this approach be applied to your production line?

If your line still counts output manually and produces several models with different Cycle Times, you can use the same approach as this case: count actual output with push buttons, calculate the plan from Cycle Time, then show the difference by time slot at the machine. What needs adapting depends on your line's count input method, model table, shifts, summary page and network, as shown in this table.

• Prepare the list of models and the Cycle Time of each model so that they match actual site conditions
• Clearly define the working time slots and break times of each shift
• Check the installation point of each station, including the board power supply and the Wi-Fi signal reaching the Server machine
• Agree the scope of on-site installation work separately and clearly