Downtime - Pinpoint The Key Problems In The Process

Downtime nearly always leads to lost production, and most companies think downtime is outside acceptable levels. More than 90% of companies record downtime to some degree, but in spite of this still struggle to make gains. What can be done now?

Turning Downtime Into Uptime

"Why is the plant not running?", How many times has that been asked? Unplanned downtime is a major issue for most manufacturers and is particularly acute for high-volume producers where it directly impacts profitability. For lines that should be running 24/7, downtime is an unrecoverable loss in terms of time and profit.

The problem many companies face is that they only have a rough idea of what's causing downtime because it is being recorded manually. When the line stops, the Operator's number one priority is to get the line running again - not to fill out paper records. Significant downtime events are recorded (although the duration may be dubious), but inevitably the often frequent yet small stops are missed.

The downtime module of Lighthouse Systems' Factory Information System, Shopfloor-Online MES, allows you to configure a set of downtime reasons for each different machine. The reasons can be classified in a number of ways, e.g.

• Breakdowns - equipment failures
• Technical reasons related to the equipment and process
• Quality-related - when the line isn't producing to the acceptable standard
• Operational - when the proper procedures have not been followed
• Planned stops - e.g. planned maintenance, change-overs, set-up
• Unplanned stops - e.g. material shortages, man-power shortages....

The latter two differentiate between stops that prevent production from starting and those that occur after a production run has begun. By classifying downtime in this way you get a handle on where the problems are coming from and where you need to focus to make a difference.

A number of standard reports like downtime Pareto analysis and downtime trends (by shift, day, week, or month) allow downtime to be analysed by machine, line, department, shift, crew, downtime reason, downtime category, product, and so on.

Manual downtime collection is an affordable and pragmatic first step. It requires no investment in data collection infrastructure, just the discipline of data capture which is usually organised on a per shift basis.

Step up to Automatic

Taking the next step to automatically capture downtime need not be expensive. With only modest investment it is usually possible to collect downtime events directly from the machines, either by connecting into existing PLCs or simply piggybacking inexpensive PLCs to collect downtime signals.

Shopfloor-Online MES allows a mixed mode environment, where those lines that warrant the added investment can have the benefits of automatic data capture from PLCs, and those that do not can have manual data collection. The situation can be reviewed at any time and manual lines can be converted to automatic.

Once automatic downtime data is being captured, not only does it reduce the demands on Operators, but it also opens up a whole new world of detail in terms of frequency of events, durations and reasons. It becomes an invaluable information source to direct process improvement work and maintenance planning.

One version of events, visible to all

All of this data is in the one Shopfloor-Online database. Not different versions for different departments, just one source of data, used by all, anyone can access it using a web-browser. It can be displayed on dashboards for all to see; it can be presented on screens and reports; and it is real-time. The state of the factory and the performance of the factory are clear for everyone to see.

Wider benefits when part of an MES

When used in conjunction with other modules of Shopfloor-Online MES more opportunities open up, for example:

• Breakdowns can automatically trigger maintenance repair orders - you can flag work in real-time, track the downtime, the response time and the repair time
• Analyse downtime to improve the frequency of planned maintenance activities
• Downtime data feeds directly into the OEE module for the Availability component of OEE, real-time KPIs can be reported and presented
• When downtime feeds into the Quality module, it is possible to verify adherence to the quality control plan taking the downtime of machines into account
• With the Documents Linkage module, useful information can be supplied to a range of users in context e.g. troubleshooting guides, set up instructions, machine manuals.