Edit in JSFiddle

var log = function(content){
    $('<p/>').html(content).appendTo('#log');
}

function doTask(i){
    // Create a new process.
    var defer = $.Deferred();

    // Start main task in the process.
    setTimeout(function(){
        log("Step " + (i+1) + " finished.");
        
        // End the process after successful finish.
        defer.resolve(i);
        
        // Abort the process if failed.
        // defer.reject(hereIsWhy);
    }, Math.random()*1000);
    
    // Report progress if the main task is lengthy.
    // defer.notify(progress);
    
    // Return read-only version of the process.
    return defer.promise();
}
    
$(function(){
    // Start step #1 in a process.
    var currentStep = doTask(0);
    
    // Chain step #2 .. #5 one-by-one.
    for(var i = 1; i < 5; i++){
        currentStep = currentStep.then(function(j){
            return doTask(j+1);
        });
    }

    // Report after step #5.
    currentStep.done(function(){
        log("All steps done.");
    });
});

<div id="log"></id>