Table:
|  | 2019 | 2018 | 2018-2019 Dollar/Point Change |
| --- | --- | --- | --- |
|  |  | (dollars in millions) |  |
| Product gross profit | $1,105.6 | $1,002.5 | $103.1 |
| Percent of product revenues | 58.6% | 58.0% | 0.6 |
| Service gross profit | $234.2 | $217.9 | $16.3 |
| Percent of service revenues | 57.5% | 58.7% | (1.2) |
Paragraphs:
The breakout of product and service gross profit was as follows:
We assess the carrying value of our inventory on a quarterly basis by estimating future demand and comparing that demand against on-hand and on-order inventory positions. Forecasted revenues information is obtained from the sales and marketing groups and incorporates factors such as backlog and future consolidated revenues. This quarterly process identifies obsolete and excess inventory. Obsolete inventory, which represents items for which there is no demand, is fully reserved. Excess inventory, which represents inventory items that are not expected to be consumed during the next twelve quarters for our Semiconductor Test, Industrial Automation and System Test segments and next four quarters for our Wireless Test segment, is written-down to estimated net realizable value.
During the year ended December 31, 2019, we recorded an inventory provision of $15.2 million included in cost of revenues, primarily due to downward revisions to previously forecasted demand levels for certain products. Of the $15.2 million of total excess and obsolete provisions, $8.7 million was related to Semiconductor Test, $4.0 million was related to Wireless Test, $2.0 million was related to System Test, and $0.5 million was related to Industrial Automation.
During the year ended December 31, 2018, we recorded an inventory provision of $11.2 million included in cost of revenues, primarily due to downward revisions to previously forecasted demand levels for certain products. Of the $11.2 million of total excess and obsolete provisions, $6.8 million was related to Semiconductor Test, $2.5 million was related to Wireless Test, $1.2 million was related to System Test, and $0.7 million was related to Industrial Automation.
During the years ended December 31, 2019 and 2018, we scrapped $9.2 million and $7.0 million of inventory, respectively, and sold $3.2 million and $6.7 million of previously written-down or written-off inventory, respectively. As of December 31, 2019, we had inventory related reserves for amounts which had been written-down or written-off totaling $103.6 million. We have no pre-determined timeline to scrap the remaining inventory.
Question:
How is the carrying value of inventory assessed?
Answer: on a quarterly basis by estimating future demand and comparing that demand against on-hand and on-order inventory positions.