THE long, linear ovens at the Simmers biscuit factory stretch into the distance, and the oatcakes and Abernethys trundle through like the ranks of a marching battalion, baking as they go.

At the end, they fall out into the hands of an army of packers, who despatch them to tea tables across the land.

It is a curiously satisfying process, and one which certainly puts a smile on the face of Mark Laing, the managing director who, six years ago, took the specialist bakery back into private hands - and a period of considerable prosperity.

He has just completed a (pounds) 2m investment in fabric and machinery, is planning

another (pounds) 750,000 tranche for next year, and is pulling in orders from the major multiples, including a ''significant'' new deal with Marks & Spencer (M&S).

''I guess we are very, very lucky,'' he said in his boardroom near Cameron Toll in Edinburgh, quietly discounting the well-documented correlation between luck and hard work.

Simmers owns the Nairn oatcake brand, the world

leader in its field. Oatcakes account, in all their guises - smooth, rough, thin, cheesy, organic - for half of the company's turnover of (pounds) 7m in the financial year to June.

The rest is earned by some tea table favourites - the Simmers Abernethy, butter biscuits, and a range of organic biscuits sold to major concerns in England and multiples such as Sainsbury, Tesco, and M&S.

''We do not actually own the Simmers brand name,'' said Laing, ''but we have it on a 999-year licence from United Biscuits, so that should give us enough time.''

Simmers and Nairns were both family bakeries which had operated on a small scale until the seventies, when United

Biscuits (UB), the UK bakery giant, embarked on a portfolio-building exercise in Scotland and took them both on as its premium brands. UB was also the stable from which Laing and his three fellow directors emerged to stage the management buyout in 1996. At that time, they were running UB plants in Edinburgh, Aberdeenshire, and West Lothian.

Their decision was spurred, said Laing, because ''there were huge demands on UB's investment pot, and this factory - which needed serious investment - was not going to get it. It was built in 1935 and needed major refurbishment. Our bid took that into account.''

Funded by HSBC, the four directors embarked on a long-term growth strategy. UB kept the Aberdeenshire factory and West Lothian was closed. In the first year, said Laing, business dropped off dramatically as Simmers lost long-term contracts which remained with UB, but thereafter growth was constant.

Turnover is projected to nearly double this year from the (pounds) 4m figure in 1996, and all investment has been funded by continuing profits. The company, which is wholly owned by the four directors, employs 100 people and is taking on more to staff a night shift for the Christmas rush.

Laing said Simmers was positioned between ''the big boys and the craft bakeries''. Its small mixes - from 25kg bags of flour rather than tankerloads - gives it enough flexibility to change the assembly line several times a day if necessary.

He said that one of his most intractable problems, in common with other Edinburgh employers, was attracting staff in a city with barely 2% unemployment.

He is also seriously worried about a recurrence of a disastrous flood two years ago which inundated the factory to a depth of three feet. ''It was a nightmare,'' he said. ''It set us back for fully a year.''

Laing said he is in negotiation with the city council about flood protection measures, on which work should start next October. Until then, he has to take the risk of further damage and said he has considered relocation to get away from the danger area.

''The trouble is that that would take another year out of the business,'' he said.