Some companies may begin negotiations earlier, but it doesn't mean the contract is resolved prior to expiration. In terms of process, we have an annual partnership meeting that takes place every November (including the outlying years). During the years we are facing contract expiration, we view this as the kickoff, and begin exploring and discussing the local issues (an easy way to categorize these is "everything going on in the plant except for wages and benefits"). Typically, we then engage in the main table discussions beginning about two months before contract expiration. Both parties are aligned to this timeline; based on experience, when you conduct negotiations over a longer stretch of time, you end up negotiating against yourselves - especially when there are significant geopolitical events that cause volatility in our marketplace and industries.
There are many contract negotiations that go on both in and outside of our industry, and the cadence of each is dictated by the involved parties and influenced by a number of factors including complexity of the issues and the parties' schedules.