Best Practices: Storing a workflow state of an item in a database?
As the previous answer suggested, I would break your table into several.
BoxItemActions, containing a list of actions that the work flow needs to go through, created each time a BoxItem is created. In this table, you can track the detailed dates \ times \ users of when each task was completed.
With this type of application, knowing where the Box is to go next can get quite tricky, so having a 'Map' of the remaining steps for the Box will prove quite helpful. As well, this table can group like crazy, hundreds of rows per box, and it will still be very easy to query.
It also makes it possible to have 'different paths' that can easily be changed. A master data table of 'paths' through the work flow is one solution, where as each box is created, the user has to select which 'path' the box will follow. Or you could set up so that when the user creates the box, they select tasks are required for this particular box. Depends on our business problem.
How about a hybrid of the serialization and the database models. Have an XML document that serves as your master workflow document, containing a node for each step with attributes and elements that detail it's name, order in the process, conditions for whether it's optional or not, etc. Most importantly each step node can have a unique step id.
Then in your database you have a simple two table structure. The BoxItems table stores your basic BoxItem data. Then a BoxItemActions table much like in the solution you marked as the answer.
It's essentially similar to the solution accepted as the answer, but instead of a BoxItemTasks table to store the master list of tasks, you use an XML document that allows for some more flexibility for the actual workflow definition.
If I'm understanding correctly, I would add the BoxItemTasks table (just an enumeration table, right?), then a BoxItemActions table with foreign keys to BoxItems and to BoxItemTasks for what type of task it is. If you want to make it so that a particular task can only be performed once on a particular box item, just make the (Items + Tasks) pair of columns be the primary key of BoxItemActions.
(You laid it out much better than I did, and kudos for correctly interpreting what I was saying. What you wrote is exactly what I was picturing.)
As for determining the current state, you could write a trigger on BoxItemActions that updates a single column BoxItems.LastAction. For concurrent actions, your trigger could just have special cases to decide which action takes recency.