tows matrix&supply chain

Most successful companies will want to be in a situation where they can use strengths to take advantage of opportunities as this generally gives maximum competitive advantage.
An ST position is considered the second best strategy. Consider an example:

A clothing manufacturer with an established reputation for quality products (S) is facing competition from cheap foreign competitors (T). The company can differentiate its brand to try and reduce the threat. But if the foreign clothes are also good quality then sooner or later the company will have to change to a low-price strategy.
Because strengths are internal and threats are external, strengths may not always address the ever changing threats in dynamic markets.

Pull model and demand centralization:
In a pull model chain, production and distribution are customer driven. To ensure that all sections of the chain are working in tandem an integrated approach is taken that passes real time demand information throughout the chain. This area can get very technical and I doubt if any such information will be required in a question.

If you’re interested:
DELL’s build to order supply chain is a good example to study.
An article by Ken Garrett “The strategic use of IT” (SA OCTOBER 2010) may be useful.