The old Public Works Department (PWD) was a national organization. Some of its landmarks may still be found across Nigeria. It had career professionals of various diversities in its employ. It had a central store, sawmills and Crown Agents who purchased materials in bulk. Because it was a countrywide organization, it was able to standardize its operations and attain economy of scale.
There was prompt availability of competent professionals, materials, stores and spare parts.
When the suggestion to use more contractors by the government was accepted wholesale, PWD became a shadow of its former self and eventually died a natural death.