"We didn't have a particularly cohesive approach to education," says Annette Di Giovanna, the company's education manager.
"So I spent time talking with customers, staff and teachers - just to try to understand what the issues were and to translate that into something coherent.
"What is it that we as a corporate body are interested in, and where can we add value? From that point of view, we are very clear about the things we will and will not do."
The company has concentrated on providing curriculum resources for schools - for example, on diet and nutrition for key stage 3 (lower secondary)-and its staff help to organise and run summer schools on food technology.
Schools can apply for grants of up to pound;5,000, but Mamp;S will not support any school seeking specialist status.
"There are simply too many of them," says Annette di Giovanna. "And how does a national corporation like ourselves make a judgement about who we support and who we don't? If you support one, why don't you support the other one? They're all looking to gather pound;50,000 of private money. It's an issue for us, so we took the tough decision and said 'I'm sorry, we will help none.' "
But where do companies draw the line? Many have policies, like Marks amp; Spencer, in which they allocate so many days every month to release their employees to do work in education.
The report, "Improving Secondary Education in London - the Business Contribution", highlights a weariness in industry about the increasing tendency of government to expect it to dip its hand in its pocket in order to support schools.
In education action zones, for example, where there have been instances of specific business skills being brought to bear at school level, these have been valued by both schools and businesses. But elsewhere, business involvement "appears to have been little more than an attempt to lever additional resources into the school".
Similarly, firms see involvement in the specialist schools programme as an attempt to secure matched funding simply to gain additional government funds for the school. And with the City Academy programme, in which businesses pay to run a single school, the benefits to businesses are unclear, says the report.
While bigger businesses are in a position to help schools in a much more structured way, the extent to which small and medium-sized enterprises get involved with education is likely to be on an ad hoc basis.
"I think they will really generate their limits themselves," says Richard Wilson, business policy executive at the Institute of Directors. "If you're a small business with 10 employees, your ability to let your staff go away and participate in a school is bound to be limited.
"And the businesses that are going to participate - in the sense of providing money - are bound to be larger because they have greater resources.
"To a certain extent, one would hope that central government would be funding schools properly so they wouldn't necessarily have to look to businesses to supplement their income.
"I don't think businesses mind making a contribution in kind or in terms of personnel. And if they're interested in the education action zones or city academies, they obviously know that they would have to put their hands in their pockets.
"But I think what would distress a lot of employers would be if the money that companies were contributing was not actually seen as an addition to education funding, but was actually being perceived as making up for a shortfall in the Government's spending levels."