private GoodsType goodsToMake() {
        GoodsType wantGoods = null;
        int diff, wantAmount = -1;
        for (GoodsType g : getSpecification().getGoodsTypeList()) {
            GoodsType produced;
            if (g.isRawMaterial()
                && (produced = g.getProducedMaterial()) != null
                && produced.isStorable()
                && getGoodsCount(g) > getWantedGoodsAmount(g)
                && (diff = getWantedGoodsAmount(produced)
                    - getGoodsCount(produced)) > wantAmount) {
                wantGoods = produced;
                wantAmount = diff;
            }
        }
        return wantGoods;
    }