Form a factory hub and shorten lead-times

All production areas in a high technology manufacturing operation - from concept to product delivery - should utilise the component design model as its hub.

A seminar on Integrated Manufacturing, staged at the 600 Centre in Shepshed, and attended by more than 50 delegates drawn from a spectrum of British Industry, depicted a streamlined virtual production operation by four leading suppliers of manufacturing software: Parametric Technology Corporation (PTC) of Warwick, Seiki Systems and CG Tech, both based in Brighton and FactoryMaster of Nuneaton.

The comprehensiveness of the demonstration was such that the philosophy of integrated manufacture could even be actioned on an international basis via Internet communications involving remote sites around the world.

According to PTC, all areas associated with production in a high technology manufacturing operation should utilise the component design model as its hub which was explained to delegates drawn from aerospace, defence, automotive, control equipment and contract manufacturing sectors.

The reasoning for using component 3D design model as the hub or reference point was that from concept to product delivery, the design has to be current.

Also with modern CADCAM, changes can be actioned quickly and easily while functions such as programming, toolpath verification and machining can all be carried out directly on the solid model dramatically shortening lead time.

According to PTC, the model in effect becomes the 'secure vault' with all the information and data pertinent to the manufacturing cycle imported, collated and recorded, verified and exported when required while being easily interfaced and seamlessly worked upon by other systems integrated into the production chain.

The four software and systems presenters at the seminar argued that when a business operates around multiple separated islands of information and databases created for each department, this leads to fragmentation of the business resulting in error and delay.

"It is more dynamic to make decisions against real time activities than historical information," they said.

From the demonstration, the four companies using the 'secure vault' concept were not only able to seamlessly interface with the model and its salient parts for communication and manufacture, but they could also gather information, relay and communicate in real time.

This ranged from quotation, assignment, change requests, task instructions, scheduling, tooling, fixturing, programming, production data and process management to production analysis, quality, delivery and invoicing.

The virtual manufacturing route depicted FactoryMaster integrating with the PTC vault to cover initial manufacturing tasks such as quotation, order receipt, material requirement planning and scheduling with the creation of the Enterprise Resource Planning (ERP) 'work-to' listing.

This data was then transferred to Seiki Systems' Graphical Scheduler which, due to its totally real-time operational mode, was able to pre-plan production on the relevant CNC machine tools according to availability, shift patterns, cycle times and production priority.

Once again closing the loop through the 'vault', the Seiki Scheduler communicated with the PTC vault data to determine availability and status of material and NC programs which initiated the PTC system to confirm availability or automatically send out a request for action from the relevant department.

Within PTC's Pro/ENGINEER design system the component model to be machined was scanned by the software to determine machining sequences to help with program generation and any proven machining strategies that were held on file, re-used whenever possible to avoid duplication and chances of error.

Once the CNC program was completed, this was transferred to CG Tech's Vericut simulation and verification software, process optimisation and Auto-DIFF module that compared the final machined model against the original Pro/ENGINEER design.

Through Vericut, true kinematic motion simulation was initiated checking dimensions, potential collisions and gouging.

It also automatically modified, if necessary, speed and feed criteria according to factors such as depth of cut before creating the NC code.

At this point, the Vericut system confirmed back to PTC that the program was proven and ready to run.

Once all the facets of the pre-production operation had been compiled, confirmed and stored in the 'vault', this was immediately fed back to the Seiki Scheduler for real time compilation of which jobs could go on each machine.

At this point, the effects of techniques such as split batching could be confirmed and once the scheduling decision was made, a programme of job queues was established and the different departments were notified with the real time requirements of tool setting, material release, gauge setting etc, for each machine.

Using the Seiki Tooling Module, all tools required for each component's NC program were compared against the tools already loaded on each machine and a tool swap list compiled.

This enabled real time based tool pre-kitting to take place with the swap requirements passed to the machine operator in order to minimise changeover time.

At a stroke, this capability negated any need for a separate tool database, any additional editing and all unnecessary or duplicated tool presetting.

When the machine was ready to be set, the Seiki software was able to provide all the setting information against the works order number by obtaining data from the 'vault' server.

This included the correct component drawing issue, set up sheets, NC program, route card information and the on-screen simulation performed by Vericut.

Most important at this stage for traceability or specification conformance was the linking of the batch order number with the current NC program fed to the machine control.

Once production was underway, the Seiki Systems software initiated its on-line production monitoring mode giving a remote real time display of the current status and the past 24 hours production.

Alarms for machine stoppage with networked messaging to call for attention were also initiated in case of developing problems such as tooling, coolant low or machine breakdown.

At the same time, in the Seiki Scheduler jobs that were on time were displayed in a 'safe' colour with immediate warning to notify of any late predictions.

This also enabled any influence of new or unplanned jobs, maintenance, or predicted delays of any kind to be viewed, with the information distributed to relevant supervision or departments.

In addition, through a special program, for any machine mounted electronic touch-trigger probes used for in-cycle probing, data could be automatically collected and collated against each job for quality traceability.

Once the batch of work was completed and the machine switched into waiting mode, the Seiki Log Book was used to generate a report on the quantity produced, scrap or rejects, waiting time or tooling stoppages and production time which was then passed back to the PTC 'vault' ready for production performance analysis to be automatically created.

Being user configurable, this could also cover elements such as Overall equipment effectiveness (OEE) with breakdowns shown in pie chart format against maintenance, tooling, setting and inspection delays, for instance, Seiki Job Related Data Capture enabled the actual job cost to be compared against the predicted cost from the quotation data created by the FactoryMaster software.

At the same time, FactoryMaster completed the works order documentation pulling together outside charges such as raw material, subcontract operations, heat treatment and plating, compiling delivery notes and invoices to complete the manufacturing loop.

* Stand-alone machine tools are under-utilised - according to data collected from CNC machine tool users by manufacturing software specialist Seiki Systems of Brighton, the average stand-alone machine is under-utilised by up to two thirds of its capacity.

In short, this expensive production asset installed to provide a high productivity solution has fallen victim of its own success due to the capability to produce smaller batches of work very efficiently.

This in turn increases the frequency of resetting between production running cycles.

Maintains David Trowell, general manager, when you look at what can be produced, especially from the latest multi-axis machine tools employing 'one-hit' machining techniques enabling a whole host of different component features to be produced in a single cycle, users are without doubt running right at the forefront of production technology.

However, as they develop their machining processes, improve methods, introduce better tooling and step up the feeds and speeds they are in fact increasing further the frequency of new job set ups against spindle running time.

"These expensive machine tools are 'key' earners to any manufacturing company and, as a result, the infrastructure of the business has to be geared in support, not only to maintain competitiveness but also to capitalise on the shortened lead time capability and to substantiate an adequate return on the investment made." At Integrated Hydraulics based in Warwick, Seiki Systems' NMS has proven to be a major contributor to the hiking of production efficiency to over 72% as well as enabling the company to function in a paperless environment with secure, traceable and efficient transfer of part programs, tooling and fixturing information.

This is taken direct from the production department to the six machining centres which operate 24 hours a day.

Not only does this provide an analysis of the actual causes but it also provides the current background to implement corrective measures.

Over the last year, according to production engineer Tony Cave, overall production efficiency has risen by 5%.

In the event of breakdown, messages are automatically sent to both maintenance and production engineers and the flagging up of waiting for tools has been remedied by the setting up of a special tooling section.

At Birmingham based valve maker FCX Truflo Marine where the Seiki Systems' NMS has been installed, manufacturing director Steve Chapman explains that the flexibility is such that should something go wrong, he can simply log-on to the planning board, even at home, to see in real time what is happening to the production of valves it carries out for the worldwide marine industry.

"I can even quickly reschedule or reprioritise jobs accordingly at any time," he says.

NMS has helped the company adopt 'lights-out' machining which has enabled cost reductions to be passed onto customers, and even track orders placed with outside contractors enabling supply to be reprioritised when required.

Truflo Marine has some 6,000 part programs on a host PC which additionally manages and stores tool lists, setting notes and even video clips of each job which are distributed to the shopfloor with full traceability against works order numbers.

All tools are kit marshalled directly to job lists taken from the Seiki Systems software so that a job cannot be set in the queue until all tooling is available and is cleared on the schedule.

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