The Navy believes its inventory of 4,000 Tomahawk cruise missiles are sufficient for future scenarios, so production is planned to end after 2016 with Tomahawk stocks to hold until the next-generation land-attack weapon is developed. Raytheon is against this action, claiming that Tomahawk production takes over 100 suppliers in 24 states, and that restarting production if needed when the line has been shut down could take two years and increase missile costs. With assessment of its replacement just beginning, it could take up to a decade to be fielded, during which time the Tomahawk stocks may potentially be depleted. Raytheon has offered an alternative plan of combining missile upgrades, including the multi-effects warhead and new target seeker, with the missile recertification program, required to keep them updated and serviced every 15 years. The company argues that combining the upgrades and recertification work on an accelerated schedule would help keep a "warm production capability" to continue production and save money for modernization