SDL Tridion 2013SP1 Event System to trigger an "Instant Approval" workflow on components that become unapproved after editing. See https://tridion.stackexchange.com/questions/8054/old-workflow-items-set-to-unapproved

Events.cs

using System;
using System.Linq;
using System.Xml;

using Tridion.ContentManager.ContentManagement;
using Tridion.ContentManager.Extensibility;
using Tridion.ContentManager.Extensibility.Events;
using Tridion.ContentManager.Workflow;

namespace ApproveOutOfWorkflowComponents
{
    static internal class Events
    {
        private const string ProcessDefinitionName = "Instant Approval";

        internal static void AfterComponentCheckIn(Component component, CheckInEventArgs args, EventPhases phase)
        {
            var session = component.Session;

            //Don't continue unless...
            if (args.CheckInAction != CheckInAction.CheckIn ||
                !component.IsUnapproved() ||
                component.Schema.HasWorkflowAssociation())
                return;

            //Start a simple automated workflow process which will Approve the component
            var instruction = new StartWorkflowInstruction(session);
            instruction.Subjects.Add(component);
            instruction.ProcessInstanceTitle = String.Format("Automatic approval for component {0} ({1})", component.Title, component.Id);
            //instruction.Assignee = component.Revisor;

            //Find the workflow process definition
            var filter = new ProcessDefinitionsFilter(session) { ContextRepository = component.ContextRepository };
            var definitionList = session.GetList(filter).Cast<XmlElement>();
            var definitionElement = definitionList.First(element => element.Attributes["Title"].Value == ProcessDefinitionName);

            if (definitionElement == null)
                return;

            instruction.ProcessDefinition = (ProcessDefinition)session.GetObject(definitionElement.Attributes["ID"].Value);
            component.ContextRepository.StartWorkflow(instruction);
        }
    }
}

EventSubscription.cs

using Tridion.ContentManager.ContentManagement;
using Tridion.ContentManager.Extensibility;
using Tridion.ContentManager.Extensibility.Events;

namespace ApproveOutOfWorkflowComponents
{
    [TcmExtension("Automatically approve out of workflow components")]
    public class EventSubscription : TcmExtension
    {
        public EventSubscription()
        {
            EventSystem.Subscribe<Component, CheckInEventArgs>(Events.AfterComponentCheckIn, EventPhases.TransactionCommitted);
        }
    }
}

ExtensionMethods.cs

using Tridion.ContentManager.ContentManagement;

namespace ApproveOutOfWorkflowComponents
{
    internal static class ExtensionMethods
    {
        private const string UnapprovedApprovalStatusId = "tcm:0-0-131073";

        public static bool IsUnapproved(this Component component)
        {
            return (component.ApprovalStatus != null && component.ApprovalStatus.Id == UnapprovedApprovalStatusId);
        }

        public static bool HasWorkflowAssociation(this Schema schema)
        {
            return (schema.ComponentProcess != null &&
                    !schema.ComponentProcess.Id.IsUriNull) ||
                   (schema.BundleProcess != null &&
                    !schema.BundleProcess.Id.IsUriNull);
        }
    }
}