Much research has been done on scheduling with constrained resources, and the findings verify what was expected — projects are completed faster when there are fewer of them struggling for attention from a limited set of facilities (Adler, Mandelbaum, Nguyen, and Schwerer, 1996). More recently, in the book Critical Chain (1997), Eliyahu Goldratt applies his Theory of Constraints — so brilliantly developed in his famous book, The Goal (Goldratt and Cox, 1992) — to the constrained resource problem. While Goldratt’s focus in the Critical Chain is on a single project with multiple demands on a scarce resource, the logic extends to the multi-project case without alteration. In the following few pages you will note that the exposition focuses mainly on scheduling. It should be quite clear by now that resource usage and project schedules are inextricably bound together. The technological necessities that force schedules to be ordered in very specific ways simultaneously force resources to be used in very specific ways. To schedule work is also to schedule resource usage. If technology is the prime force behind scheduling the activities of a project, resource availability constrains all solutions to the scheduling problem. To begin our discussion of Goldratt’s approach, imagine for the moment that you are sitting in a room full of people with extensive experience as both project team members and project managers. Now imagine the responses you would hear if the group were asked the question: “What things bugged you most about the projects you have been involved with?” Typical of the responses that we have gotten to that question are:  Project due dates are too often unrealistic.  There are too many changes made in the project’s scope.  Key resources and data are often unavailable when needed.  The budget is frequently unrealistic and therefore often exceeded.  It seems like my project is always in competition for resources with other projects. One interesting observation is that these same issues are raised regardless of the organizational context. Thus we hear strikingly similar complaints regardless of whether the group is referring to a construction project, a software development project, a project to develop an advertising campaign, or an R & D project. Hussain and Wearne (2005) asked more than 1000 project managers to identify the “greatest problem of project management”, a subtly different question than we asked, and they found that project “organization”, “resource”, and “time” issues were paramount. (“Change in scope” was ranked 11th in their research.) Based on these findings, it is not farfetched to conclude that the causes of these problems are generic to all types of projects. Project management is fundamentally concerned with effectively trading off scope, cost, and time. Referring back to the lists of complaints, it can be seen that each issue (excepting “organization”) deals with one or more of the three primary project objectives. Given our conclusion that the problems encountered when managing projects are strongly related to the need to trade off one project objective for another, a natural question arises about the extent to which the need to make these trade - offs are caused by human decisions and practices. In other words, can more effective project management minimize the occurrence of these problems? Source: Mantel, Meredith, Shafer and Sutton (2011)

QUESTION 1 (30 Marks) Critically discuss what is meant by Goldratt’s critical chain as referred to in the case study, and how effective it is in scheduling resource constrained projects. Present examples to illustrate points crafted in the discussion.