Preactor Scheduling Excellence not only Skin Deep

Metal Improvement Company's factory in North Wales near Chester is a purpose built facility to form large, expensive machined aluminium alloy panels for the wings on the Airbus Industrie family of passenger aircraft. The panels are formed by controlled shot peening. Shot peening is a technique of bombarding a metallic surface with spherical shot so as to induce a compressive surface stress. The residual stress shapes the panel and simultaneously increases its fatigue strength.

In the early '90s Metal Improvement were faced with a significant scheduling problem which was becoming increasingly complex due to a combination of several factors.

The original task for the facility, in 1982, was to form panels for the A310 aircraft only. In the intervening years new projects had increased the work load to include panels for the A319, A320, A321, A330 and A340 aircraft so that there is now a choice of over 30 different types of panel which are required to pass along a line of 17 work centres. Each work centre has up to 4 resources though not all panels could fit onto all resources. The total number of work centres used varies for each panel. The panels range in size from 1.2 m x 9.0 m long up to 9.2 m x 21.5 m long. The customer, British Aerospace Airbus recognised the need to reduce inventory costs and Metal Improvement wanted to help with this objective. It was very clear that the existing paper based scheduling system allied to a simple Kanban type board held on a PC would not be able to arrange the variety of tasks in the best sequence to give the best possible turnaround times on these long lead times in a reasonably assured, predictive way.

A search was set in motion to find a PC based system to scheduling Metal Improvement's Airbus forming facility. Many systems were investigated with no success due to either the high cost of some of the commercially available systems or the very limited capability of other project type programs. Even so a short list of 3 systems were compiled and discussions proceeded over several months to reach an agreement. The principal difficulty lay in the "all can do" nature of these systems which drove the price of the software beyond any realistic budget price. Two suppliers were prepared to offer a limited system, but even so the costs were still too high.

In the Spring of 1994 Preactor International presented their Preactor 200 FCS scheduling system at a price that was fraction of the other systems previously assessed. It looked like it would give Metal Improvement a method of scheduling the panels through the factory without the need to purchase all the other unwanted facilities offered by other systems. The decision to buy was made in July 1994 and installed of the system commenced in mid-August. By the end of September Preactor 200 FCS was up and running alongside the old system. By the end of October it was scheduling all the panels as a stand alone system.

Whilst it is not correct to say that all components are now always produced in a faster time than in the pre-Preactor days, as there were times when the factory resources were fully utilised, it is true to say that it is now possible to predict completion dates far more accurately and so minimising expensive inventory. It is estimated that inventory values are now lower by 25%.

The user friendliness of Preactor has been a major factory in its speedy installation at Metal Improvement. It was set up by the Production Manager (who would not claim to any great expertise in computers) with the first class on line assistance of Preactor International. The willingness of Preactor International to customize the program to match MIC's needs has been a significant factor in its acceptance on the shop floor.