AVEVA, the FTSE 250 engineering software company, claims that it has made good progress in the first half, but has warned of weak demand in North America and obstacles in China.While Oil and Gas continues to be the main driver in the majority of AVEVA's regions, the company has seen weak demand for its Engineering and Design tools in North America, and the planned reorganisation in China has had a short term impact on revenue there.As a result of this reorganisation in China, the group confirmed that - as highlighted previously - full-year revenues will be weighted heavily in the second half. As such, adjusted pre-tax profit in the six months to 30 September were just slightly ahead of the previous year."Once the benefits of the new China organisation are realised, we expect further momentum to be gained in the second half of the financial year."The Enterprise Solutions division performed strongly, with revenues "substantially ahead" of last year."Following the change in our organisation to bring more focus on Enterprise Solutions, we are delighted to see further progress in this area with significant rates of growth in the first half," said chief executive Richard Longdon."This progress, along with the continued strength in Latin America, means we approach the second half of the year well positioned and we expect to deliver the board's expectations in the second half", he said.BC