For Dennis Selsky, a Vietnam-era veteran with multiple sclerosis, it was lost documents. It seemed that every time he sent records to the Department of Veterans Affairs, they disappeared into the ether.

For Mickel Withers, an Iraq War veteran with severe post-traumatic stress disorder, it was a bureaucratic foul-up. The department said he received National Guard pay in 2009, though he had left the Guard the previous year, and cut his disability compensation by $3,000. He filed for bankruptcy to protect himself from creditors.

For Doris Hink, the widow of a World War II veteran, it was the waiting. The department took nearly two years to process her claim for a survivor's pension, forcing her daughter to take $12,000 from savings to pay nursing home bills.

These are the faces of what has become known as "the backlog": the crushing inventory of claims for disability, pension and educational benefits that has overwhelmed the Department of Veterans Affairs.

Numbers tell the story. Last year, veterans filed more than 1.3 million claims, double the number in 2001. Despite having added nearly 4,000 new workers since 2008, the agency did not keep pace, completing less than 80 percent of its inventory.

This year, the agency has already completed more than 1 million claims for the third consecutive year. Yet it is still taking about eight months to process the average claim, two months longer than a decade ago. As of Monday, 890,000 pension and compensation claims were pending.

Skyrocketing costs have accompanied that flood of claims. By next year, the department's major benefit programs -- compensation for the disabled, pensions for the low-income and educational assistance -- are projected to cost about $76 billion, triple the amount in 2001. By 2022, those costs are projected to rise to about $130 billion.

"We're not gaining any ground here," Eric K. Shinseki, the secretary of veterans affairs, acknowledged in an interview over the summer. "Am I impatient? Yes, but I've got a fix."

That fix is the department's "transformation plan," which calls for a new training regimen that Shinseki says will improve speed and accuracy in processing claims; creation of special teams to handle complex claims; and new digital technology that will replace the current paper-choked system.

Current and former front-line workers, who spoke out of frustration with the widespread criticism of their agency, offer a different analysis. The dysfunction, they say, stems from inadequate training and weak management, an excessively complicated process, and assembly linelike performance standards that require them to meet production quotas under threat of demotion or firing. The solution, they say, is clear.

"They need more workers," said Mark Locken, a retired Army artillery officer who worked for the department for three years in Boston before quitting in May because, he said, of the stress.