Archive for the 'CPM' Category

There's nothing like learning-in-action.¹. We just finished our planning session for our development project. I was surprised by how much time we spent defining what it meant to be done. In the LPS world we call that establishing conditions of satisfaction. But we struggle to get team members to stay in that conversation. "Just tell me what you want!" The ScrumMaster wouldn't let us move on 'til he confirmed that the whole team understood what would satisfy the Product Owner.

I'm looking forward to comprehending!

Towards the end of today's session, I noticed that our ScrumMaster frequently said, "We'll inspect and adapt." (He said it before we started the planning. I just hadn't noticed.) "Of course," I thought. The future is uncertain and unknowable. That's just what we do on (LPS) projects. But I also know it's not what is usually done on CPM-style projects. Conventional wisdom (and scheduling software) guides people to put a plan in place and stick to it. The result is project managers often try to get reality to match their plan. Doesn't work. Never did.

Read the rest of this entry ¶

1. Chris Argyris claims it's the primary way we learn. See his book Knowledge for Action. [ ⇑ back ]

Hard to imagine in the world of projects that anyone would ask the question "Why do deadlines matter?" However, in the world of politics and world conflicts the argument is front and center. We learned this week, President Bush just won his battle with the Democrats in Congress. There will be no deadlines in the funding bill for the war in Iraq. To my surprise, I opened the June issue of Business 2.0 turning to Jeffrey Pfeffer, Professor, Stanford University, to see his essay Why Deadlines Matter. Read the rest of this entry ¶

Progressive Project Delivery is the name of ENR's special report in the November 13, 2006 issue. They highlight a number of "leading practices" including an innovative approach to contracting for the 2012 London Olympics. But sandwiched between the story on the Olympics and another on a program to build or remodel 70 Greenville schools is the announcement of a service for "setting up and managing critical path method schedules and updating them monthly." The service is offered by Quality Planning Solutions, Inc. (QPS), a subsidiary of the construction powerhouse Turner Construction.

I don't know anyone who would say, "Thankfully we had a CPM schedule that we always kept up to date." Rather, the not-so-secret dirty little secret is that project teams ignore the CPM schedule. I've written extensively on CPM scheduling. Here's one of my favorites CPM: What Do You Prefer?

Good luck QPS and their clients. Let's hope they find real value.

[Notes from LCI's 7th Annual Lean Construction Congress]

"(Lean transformation) doesn't always look pretty!"

Paul Reiser, VP The Boldt Company, is one of the leaders and contributors to the development and practice of lean construction. He has been splitting his time between hospital projects and paper mill projects. The Boldt Company has been growing steadily and diversifying along the way. Pulp and paper investment has declined substantially in the last 10 years. Boldt's business has shifted from 70% of their work to 10%. They started using LPS on building projects in 1999. The paper rebuild clients thought they already do it. LPS didn't take. The fragmented contracting of specialized labor got in their way. The pulp and paper industry uses CPM schedules to capture and roll up individual trade planning. Productivity was tracked using earned value. For the most part things went well.

Three factors changed the situation for lean:

1. Companies are more concerned about opportunity costs of outages. Paper machines make between $21,000 and $42,000 of profit/day. A 30-day outage can mean a loss of $1 million profit.
2. Availability of a web-based tool for LPS.
3. Helping Hands agreement with the trades.

Early initiative confirmed the opportunity. The stage was set for more collaboration and eliminating barriers between the trades.

Demo and rebuild was planned for 10.5 days working 2 shifts 24 hours/day. Boldt created a teaming agreement among the main contractors that said they would share the all the risks, labor, and no back charges.

Boldt was invited late to the project. The project had a typical push CPM schedule. They went ahead anyway. Dumped the CPM schedule into LeanStream. They didn't have the appropriate level of participation or knowledge for leadership. They used their daily planning sessions to update their commitments. They tried to accomplish too much into a 15 minute meeting. PPC trended downwards. People over committed. Work shouldn't have been on the plan. Due to a surprise with some foundation work they got 4 shifts behind in the first few days. This created the opportunity to use a pull planning approach to replan the start-up with only 8 days left in the project. Following this session PPC trended towards 100% PPC. The owner was impressed with the recovery and asked for an improved planning process for the next machine rebuild. The nature of lean transformation is it's not real comfortable at first. It doesn't always look pretty.

The second project was done with more traditional LPS approaches.

• Sequenced the work aided by 3D modeling
• Did a multI disciplinary pull schedule
• On the floor updates of commitments
• Focus on commitments at shift change

The team finished two days earlier than the fastest a machine of this type had ever been rebuilt.

What's next? 5S for the projects. The underlying operating system must be changed. Lean provides that basis for that change.

Audience Understood Key Points

• Engaged the unions for buy-in and participation
• Were able to recover the delays with the use of lean tools
• Can't dump CPM into lean scheduling
• Setting the bar and setting the process to meet it
• Even a less than well-working LPS still produced better results
• Ability to use LPS to adapt to the unexpected
• Sr Planner finally became a convert that CPM was only good for strategic planning
• Break down provides the opportunity for break through
• Have realistic implementation expectations. Let the team learn and fail.
• Impressed by the leadership of Paul Reiser
• Integrated agreement for resources, risks, and rewards
• Startling that the GC didn't backcharge the subs for what subs should be doing anyway

Questions

• What kind of integrated agreement was it?
• Why did you use 3D modeling in sequencing and strategy?
• How did you select subcontractors?
• Tell us more about LeanStream?
• What was the negotiating strategy to get the unions to work together?
• How are you applying lean back office?

Paul's Closing Comments

It was too much of an effort to use 3D for sequencing. We have more to learn.

LeanStream is SPS's tool for supporting LPS.

We used our standard subcontract form but we appended it with a teaming agreement. We used it to get specific about the behaviors we wanted to see on the project.

Our common sense understanding of projects has us believe there is a critical path that must be followed if we are to be successful on our project. Many contracts require that an 'accurate representation of project priorities' be represented as a critical path. Here's what I said in my state of the art assessment:

6. There is no critical path. Of course I'm not saying that one can't calculate a critical path. Of course you can calculate it. I'm saying that it is not a thing, just a characterization.

Like anything, a CPM schedule is only as useful as the data that is available for doing the calculations. CPM schedules use task and duration data for the calculation of the critical path. The problem is the data is not fact. The only project facts we have on task effort and durations is available after the tasks are completed. At that point critical path calculations have limited value.

The dirty secret of construction projects is the critical path schedule is not critical.

Schedules are constructed using estimates of task durations and task dependencies. Goldratt showed us the effects of dependence and variation on the predictability or reliability throughout a project. At best we have reasonable estimates. But they are estimates. Rarely do people take the time to produce estimated ranges of effort and duration. Consequently, our schedules fail to represent the stochastic (probabilistic) nature of the project. Yet we treat our schedules as if they are deterministic. This is the fundamental flaw in our use of the critical path method.

The dirty secret of construction projects is the critical path schedule is not critical. Construction superintendents and project managers have their own set of priorities that dictate what gets done first. For more on my views read: CPM: Fool Me Once, Fool Me Twice.

What is the project manager to do? Paraphrasing David Schmaltz, project managers already know what to do, and many are already doing it. How about the rest of you?

Over a year ago I published a series of postings on the critical path method that produced all kinds of comments and emails from readers. I collected those postings into a two-page article that I published on this site as CPM: Fool Me Once, Fool Me Twice. Shortly thereafter, Greg Howell caught some article in ENR on CPM. It was the usual stuff about project managers just need to learn how to use the CPM tools. In an unpublished letter to the editor (with a copy to me) he replied this way:

"CPM is the tool for you if you believe what you know is more important than what you can learn, and if you prefer being "In Charge" to getting the project done, and if out-of-date plans are more useful than a team prepared for action."

Without promising the project is full of delay. That is waste. And it leads to more waste.

While I see what he is saying, and I think the phrasing is clever, many people might not get why he says it. Greg is indirectly pointing to the stasis of the use of the CPM tools. People don't have the habits or the inclination to keep the CPM schedules up-to-date. Little variations and missing task status can throw a CPM schedule out of whack. Soon people lose confidence and ignore the schedule.

Another key issue has to do with the authorization of work. The PMBoK® says something like, "Work is authorized by the schedule." Authorization is not the issue. Coordination among the team is the issue. Team members depend on the completion of work (prerequisites) so they can begin their work. But beginning work is the easy part. Other team members want to know when you will finish your work. They, just like you, want a promise. Without promising the project is full of delay. That is waste. And it leads to more waste.

Team members can make promises on the work they will perform informed by a CPM schedule. That would be wonderful. But we don't see that behavior. In fact, we see, as Greg so aptly puts it,

"The usual project meeting is a commitment-free zone." The CPM schedule is just one of the excuses for not doing what needs to be done."

What do you prefer? I don't know anyone who would identify with Greg's characterization. And teams need some guidance of overall sequence of work. Bob Huber, Scheduling Manager, The Boldt Company, suggests The Marriage of CPM and Lean Construction in his paper co-authored with Paul Reiser presented at last year's International Group for Lean Construction's 11th Conference. He urges people to use CPM at a high level rather than a detailed task level. Further detail is left to the people performing the work. The result is a CPM schedule that is easy to keep up-to-date and doesn't have swings in it from week to week. People will use that schedule.

I received this email today. As I prepared a reply, I decided to share it with readers of this weblog. I started answering with the mechanics of delivering projects on a lean basis, but then it occurred to me that one needs to see their role differently to deliver projects with far less waste, higher schedule and cost reliability, and so much safer.

Hi Hal,

Please help me understand:

The CM needs an approach for bringing the interests of the specialists into alignment with the promises to the customer.

Our role in construction projects is either general contractor or construction manager (CM). We plan our projects using master CPM schedules and two-week look-ahead schedules for site activities. Typically we do not self-perform any work. How do you apply the Last Planner™ and the "pull principle" in such an environment?

Bosko

Great question. As CM you are responsible for the completion of your promises to the customer. Sub contracting doesn't shift that responsibility. You are still responsible. But how do you carry out that responsibility?

Normally, a CM hires numerous Subs to perform specialty roles. These Subs interact with each other to produce the finished spaces. Each Sub naturally acts in their own interests seeking to optimize their use of their labor, equipment, and materials. This local optimization of resources leads to an overall reduction in the productivity, risk to schedule performance, and higher costs. The CM needs an approach for bringing the interests of the specialists into alignment with the promises to the customer.

The approach has three steps:

1. Backward schedule just that work that adds value for the client. Produce this reverse phase schedule in conversation with the primary Subs on your project.
2. On a six-week look-ahead basis prepare the work, wherewithal, and the circumstances for completing the work on the reverse phase schedule so that each task can be started and completed without interruption. Continue to review and make-ready the work adding a new week from the schedule each week.
3. Have crew leaders (last planners) have public planning conversations where they promise the completion of only the work that has been prepared (ready). The weekly work plan (WWP) is the sum of the promised tasks. Use the WWP to guide what is done on a daily basis. Also use it to measure how you are performing and to learn from planning failures.

Your aim is to have tasks completed as promised. As CM you have a project manager and site superintendent for the project. Their roles shift from controlling (after-the-fact monitoring) and motivating (carrot and stick) to engaged planning, preparing, and navigating with those people performing the work. The essence of the your work as CM is to see that performers are in a position to be successful with their efforts.

Lean projects require more conversation, more engagement, and more teamwork. Your role is to be the leader that brings all that about.

You can find the PDF of CPM: Fool Me Once, Fool Me Twice in the left column of the weblog. Or, get it here .

Previous in series

Some very thoughtful comments were made on some of the postings from last week's series on CPM. I urge you to read those comments. Just click on the "(#) Comments" link at the end of each posting wherever you see a number other than "Please Comment". I urge you to leave comments as well.

If what people were doing was working there'd be no reason to do something else!

A few people asked me what I was planning to do with the Fool Me Once, Fool Me Twiceseries. Based on the requests I've decided to compile the five postings as a single document that I'll link on the site. That document can be freely downloaded and distributed. I hope you find it valuable.

Now for those wondering what got me going on the series in the first place, I've been somewhat concerned about people who set out to adopt a new approach (to anything) while trying their hardest not to give up what they are doing. If what they were doing was working there'd be no reason to do something else! We know in the case of project planning and control that it routinely doesn't work.

Continuing to do the old has three negative effects on succeeding with the new:

1. It maintains the inertia of the current practice
2. It consumes scarce attention and capacity for adopting the unfamiliar and initially time-consuming practice
3. It reinforces the measurement and rewards associated with the old

Using the Critical Path Method for project planning and control is just one of those practices that seems like a good idea, but fails in execution. One issue I failed to stress last week is the lack of seriousness given to CPM as evidenced by not providing the resources to do a good job keeping the schedules always up-to-date. There is a trend seen in construction where people are preparing the CPM schedules yet they don't know how to build and don't know scheduling¹. Lack of seriousness and competence spells disaster for the project participants. Not doing CPM scheduling in many cases would be far better than doing it the current way. And certainly for those people who are dissatisfied enough to try a different approach they should give up trying to do both.

Stop the craziness of doing the old and the new.

1. As reported in ENR [ ⇑ back ]

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Planning is conversation.

The future is uncertain and unknowable. Commitments must be adjusted as the future unfolds. Those adjustments can be done by the project manager or anyone on the project team. However, only those people involved in planning the project will be in the position to notice and then assess the need for adjustment.

Stay in conversation with all key performers and insist they do the same with those people supporting them.

So, why use critical path? All planning is practice. Each time through a project plan the participants prepare themselves for the future that is unfolding. Will it turn out just as they plan? Of course not. But taking the time to plan prepares them for the eventuality of the future being different than they expected.

Do you want your projects to finish on time and on budget?

• Accept the plan as represented on the critical path is what will not happen; task starts and finishes are uncertain.
• Investigate the level of effort for every task on the critical path. Adjust buffers in accordance with the circumstances and the competence available.
• Make assignments only when the work is ready — prerequisite work is complete and resources are available.
• Measure the performance of your planning practices as a basis for eliminating the sources of task variability.
• Include performers in planning conversations to give them practice for the inevitably uncertain future.

Let's stop fooling around on projects. Stay in conversation with all key performers and insist they do the same with those people supporting them. Use those conversations to continue exploring possible ends and means. It is the one and only avenue for succeeding with projects.

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Task durations depend on the quality of the conversations.

Schedules are not commitment. We have been fooled enough to know that! Just because we say a task is on the critical path doesn't mean it will get done. Only when the intended performer promises to perform will it get done (and even then, maybe not). Commitment is produced in conversation. When people freely promise there is a possibility of commitment. Absent conversation, tasks will not complete as desired.

Declaring complete — saying, "I'm done" — is the step to keep work flowing.

Declaring complete is the key action for keeping any project on track. People do not do what the schedule says they should do. Yet, project managers too often expect that people will do just what the master schedule says they should do. Why? We can't do tasks that are not ready to be done. Tasks on the critical path necessarily must wait for the task preceding it. Unfortunately, performers in sequence may not be in conversation with each other. They don't know that a task is complete therefore releasing the work for the next person in line. These performers may work in different divisions, companies, or just not be aware that another person is dependent on them. Declaring complete — saying, "I'm done" — is the step to keep work flowing.

One-way communication doesn't work. Project members are informed of the schedule. Performers are told which tasks they should do. Status is given as a report by someone other than the performer. None of this produces commitments. You must be in two-way conversation to have people perform to the schedule. Only the fool thinks "telling" suffices.

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Task durations vary.

Experienced project managers will tell you the critical path moves on a project. Why? Tasks don't start and finish as represented in the project schedule. This would be fine if all the performers for critical path tasks were always available to perform on the project, but this is not the case. In most organizations people are working on more than one project at a time or project work is in addition to their normal work responsibilities. This creates the situation where they must manage priorities: "Do I spend my time on this or on that?"

Our only avenue is to manage the project to minimize the variability.

We don't know all of what must be done. Oftentimes ad hoc work (those tasks that seem to arise in the course of doing the other work) encompasses as much time as the planned work of the project. To the extent that this ad hoc work requires the same resources as the work on the plan we see projects get behind. Performing this work often shifts the critical path.

Task durations therefore are probabilistic. They will range from times that are as short as the actual time applied performing the task to as long as multiples of the task times depending on how much waiting time and distraction time is incurred. Projects by their nature make it difficult to gauge those probability distributions because each project is unique. Our only avenue is to manage the project to minimize the variability.

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Task durations are fabrications.

Let's say you produce a critical path (for whatever reason). The generally accepted approach is to ask each key performer to provide durations for the tasks and the precedence relationships. With this data you can find the longest path through the network of tasks. With this approach you overcome one of the problems previously identified. So, is there still a problem? You bet.

We can safely assume that all durations are at least twice as long as they need to be.

Success with the critical path method hinges on knowing task durations…how else are we to coordinate action? Each person will estimate the time it will take them to perform. If they are at all risk averse, then they will also buffer that duration based on their experience performing similar tasks. Why? Because they don�t want to be the person responsible for getting the project off track. However, we don't know what those buffers are. One person might add a 20% buffer while another adds a 500% buffer. Eli Goldratt, author of Critical Chain, and founder of the Avraham Goldratt Institute, suggests we can safely assume that all durations are at least twice as long as they need to be.

What are we to do? We must investigate task level of effort (estimated hours to perform) for every task on the critical path and consider carefully its application. Durations alone are not sufficient. We are fooled twice when we accept durations as stated.

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Task durations are estimates.

The critical path method (CPM) is considered THE standard for managing projects. Customer contracts often require developing and maintaining the critical path schedule in great detail. Universities teach CPM in project management courses. CPM is the primary function of the best-selling project management software. Large plots of project schedules hang in construction trailers and project management offices depicting the network diagram and the critical path. No project professional in his or her right mind would start a project without calculating the critical path. So, if it is so widely used, then why are projects late, over budget, and dissatisfying customers?

Knowing who will perform and the circumstances for performance make more of a difference.

We are fooled by the critical path. The central presumption for establishing a critical path is that we know how long each activity or task will take. When the activities are then strung together according to precedence relationships one can find the minimum time through the project. That is the critical path.

So what is the problem? How could you know what the real time will be for completing a task? You can't. It is complicated by not knowing exactly who will be performing the task. (Rookies take longer than experienced people.) And it is further complicated by not knowing the circumstances (or situation) for performing the task. (Even experienced people can be distracted or can have an off day.)

So what does this mean for anyone managing projects? If you think that managing a project means just keeping your eye on the critical, then you are mistaken. Knowing who will perform and the circumstances for performance make more of a difference. Don't be fooled.

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