The fall from grace that Alcoa (AA) has suffered in the eyes of shareholders in recent years has been devastating, with the former giant in the industrial sector seeing its share price fall in line with the plunge in aluminum prices in recent years. Sluggish demand in certain areas, combined with a big jump in supply from low-cost manufacturers, forced Alcoa to respond with intensive restructuring efforts. Even though the stock remains under pressure, Alcoa's move to recast itself has paid off operationally, and the company now finds itself with some substantial opportunities for future growth. Let's look more closely at Alcoa's success stories to pinpoint which areas have the most potential to drive the company forward in the years to come.

1. Aerospace
The aerospace industry has always been an important source of business for Alcoa, given its need for lightweight materials that are both durable and fuel-efficient. With the boom in demand for new aircraft in the commercial aviation sector, Alcoa has ramped up its supply both of vital raw materials and, more important, of value-add designed products that it manufactures specifically for aircraft producers.

Alcoa's recent acquisitions have dramatically broadened the company's reach in aerospace. Firth Rixson has allowed Alcoa to double its average revenue content on important jet-engine programs for major aircraft manufacturers. TITAL has accelerated Alcoa's expansion beyond aluminum into other lightweight materials, with titanium also playing a key role in producing customized components, parts, and other products for the aerospace industry. When the company's acquisition of RTI International Metals is complete, Alcoa should get even wider distribution of its products throughout major aircraft designs.

Alcoa sees demand for the aerospace industry continuing to rise, with the pace among the fastest of its business segments. In its earnings report last week, the company said that production plans for the Airbus A350 and the Bombardier C Series of aircraft won't occur as rapidly as originally thought, but Alcoa still sees 8% to 9% growth in 2015. Moreover, in the years to come, Alcoa thinks that annual sales growth will accelerate to as much as 13% by 2017.

2. Automotive
The automotive industry has also been a solid long-term performer for Alcoa, and even though the company's near-term estimates for growth prospects in the industry aren't as strong as for aerospace, it's clear that automotive applications have huge potential for future expansion.

Many see automotive customers as primarily a midstream opportunity for Alcoa, with the company having grown its automotive-sheet production capacity through initiatives like its Davenport plant expansion. Automotive-sheet revenue nearly tripled year over year in the second quarter. Moreover, advanced technology that went into producing Alcoa's Micromill material allows customers to build components and parts that are easier to form and substantially lighter than similar high-strength steel products, all while making the production process more efficient on Alcoa's end.

Alcoa investors probably won't see a big immediate impact from the automotive sector, with the company calling for just 2% to 4% global growth in sales and North American sales climbing just 1% to 4%. Yet with more manufacturers looking to integrate lighter-weight materials into their products, the auto sector remains a core focus for Alcoa in its efforts to maximize its revenue.

3. Upstream alumina and primary metals
One of the most surprising successes that Alcoa has seen lately is in its upstream production. When it first revealed its restructuring efforts, many investors saw it as a virtual surrender, with large numbers of plant closings. Yet the strategy has been one of replacing high-cost production with lower-cost alternatives rather than simply getting rid of the upstream business entirely, and the result has been a huge reduction in expenses that has made Alcoa one of the most competitive producers in the world.

To be clear, Alcoa has been willing to reduce its overall production in response to poor conditions in the aluminum-commodities markets. It cut global smelting capacity during the second quarter by almost 100,000 metric tons to 3.4 million, and it also curtailed nearly 450,000 metric tons of alumina refining capacity in Suriname as it seeks to try to sell off its operations in the country to a state-owned company. Yet when you combine Alcoa's total operating income for alumina and primary metals, it more than doubled from the year-ago quarter, despite mixed performance over the past year for the underlying commodities on the global market.

Alcoa has correctly identified numerous strategic opportunities to pursue, and so far, it has done a good job of making the most of all of them. Investors should watch out to see which of these possible directions Alcoa ends up moving most aggressively toward and whether the potential for profit keeps building over time.