How many fully functional old smartphones are we still keeping?

Even though they normally have no phone line they still have multiple uses such as listening to music or watching videos. 

But can they still be useful in our work?

In an area with WIFI there are still multiple work applications for these old phones which might save on expensive IT applications.

One major advantage of using these phones is that the skill is already there: a new IT application would require training. 

Some Possible Business Uses for an Old Smartphone with no Phone Line

  1. Workplace data collection in real time
  2. Incident reporting anywhere any time
  3. Maintenance repair action reporting from anywhere when it is complete
  4. Value Stream Map building and validation in Gemba (where the action is)
  5. Real-time Statistical Process Control
  6. Real time manufacturing status display for all those concerned

 Workplace data collection

Pencil and paper data collection is still very common even in high-tech manufacturing industries:

This approach, apart from being time consuming, makes it impossible to control the process in real time.

An alternative is to collect the data in a spread sheet in the cloud (Google Drive, One Drive, Intranet, etc.) using our old smartphone connected via WIFI.

Defects can be detected anywhere along the process and it may be inconvenient to go to the nearest terminal to report. With our old smartphone we can report the defect in our spreadsheet in the cloud but also make a photo and attach it to the file so you don't need any additional explanations.

This approach enables data entry validation avoiding data entry errors.

Data entry could be done with pull-down menus to avoid typing.

Timestamps can automatically be added to register the reporting time.

In case of having to enter a written clarification text can be entered with voice from the smartphone.

 Incident and Repair Action Reporting

Incidents affecting the process may take place anywhere any time. If reporting is done at a later stage time information is lost: when exactly happened. This information is critical when it comes to failure analysis: correlation with process parameters or other incidents, etc.

By using our smartphone we are able to report it when it happened and the timestamp can be automatically added. 

The maintenance spreadsheet in the cloud can keep track both of incidents and repair actions by the maintenance department. 

Pull down menus can be used to report the equipment, component, failure, etc. and this will enable the maintenance department to track failure frequencies and get to the root cause of problems. 

Incidents can be classified by urgency to enable maintenance assign priorities. Pending actions already late are marked in red and due actions in orange. 

Using a smartphone simplifies reporting of both incidents and repair actions.

Association of defect type and repair action is also possible with this integrated worksheet helping Maintenance in their diagnostic.

Value Stream Map building and validation

A Value Stream Map of the process we want to improve is built after visiting the line where the process takes place. 

This VSM can be built in a spreadsheet in the cloud by using a smartphone from the line itself:

  • The VSM is built directly in the cloud (Google Drive) and all participants visiting the line have write access with their smartphone.
  • As they move along the line they all agree on who is doing what and when.
  • Typing of the process steps in the Excel sheet can be done by voice. 
  • The VSM, as it is being built, can be shown to the line operators in order to validate it.
  • After the VSM is complete the same method can be used to collect process parameters (process time, WIP, etc.) in the VSM Excel visiting the line.
  • An Excel file can be used to measure and collect process times with the smartphone:

Real Time Statistical Process Control

 Statistical Process Control (SPC) requires real-time data collection in the different control points. It may be difficult to provide terminals in all these points to report so our old smartphone may be a valid alternative by building our SPC chart in a spreadsheet in the cloud (Google Drive, etc.)

This Individuals-Moving Range SPC chart applies the Western Electric rules to detect out-of-control situations in real time as the data is being entered. 

This chart is visible to the operator entering the data with his smartphone and also to the operators responsible for that process step with a tablet or PC connected via WIFI to the Google Drive spreadsheet.

In this example there is a significant drop in yield between 10:00 and 16:00 (4 out of 5 consecutive values more than 1 sigma below the average)

 Real Time Manufacturing Status

In order to keep everyone involved in the process informed on how are we doing we need this information to be available and up to date at all times.

 A Gantt chart can show the plan and it could be updated by the production system or by the person responsible with a smartphone. 

An Andon can be displayed in the line to show the status but also accessed from the smartphones to see how are we doing. In this example:

  • Component manual insertion DPMO (Defects per million insertions) is 4124: above the target of 1500 (RED)
  • Pin-Thru-Hole wave solder DPMO (Defective solder joints per million joints) is 32: below the target of 190 (GREEN)
  • Current throughput: 13 cards/ hour at 13:55 on 15/11/2005 at the PTHHW station

With this real-time information the operators involved can react before it is too late and correct the situation. 


An old smartphone, even if not the latest generation, may still have a useful life in your business by using your existing WIFI to connect to the cloud.

Data collection in real time is one of the most useful applications even if the smartphone has no phone line connection.

Since everyone already has the skills you can easily implement these proposed solutions to control your process in real time and keep everyone informed at all times.