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Accurately scoping process analyzer projects

Oct. 10, 2006
This article covers the formal details of a project approval scope document, including front-end engineering design, front-end loading, project execution modeling, and independent project analysis.
By Gary Nichols, PE, Jacobs Engineering Group

THE FIRST article in this series (“How to Launch an Analyzer System Reliability Program,” Control, July 2006, pp 49-53) noted the close relationship between the lifetime cost of a process analyzer project and the attention given to reliability during the concept (scope development) and design (detailed engineering) project stages. This article covers the details of a project scope document. 

One of a project engineer/manager’s most challenging jobs, especially during project scope development, is the avoidance of “meatball engineering”—a poorly scoped project that leads to minimally effective results. (Gregory Hale, InTech, Oct. 2004) Key to this avoidance is “knowledge management” and “good client” development, says Hale.



How to launch an analyzer system reliability program



The engineer must elicit from the client—the funding source—all the information required for a good project and gently, but persistently, minimize chances that he becomes his “own worst enemy,” causing unwise scope-cutting or, conversely, “scope creep,” or demanding  procedural shortcuts, illogical cost-cutting and schedule changes. The project engineer must ensure communication with clients or accept--often unjustly--responsibility for missing project goals, and it falls to him or her to make sure this doesn’t happen. (Mark Hoske, Control Engineering supplement, Dec. 2004, pp.12-14)

The information that must be addressed is often part of the front-end engineering design, the front-end loading, the project execution model, and the independent project analysis. (R. Mead, H. Sedgwick, and S. van Soest, Hydrocarbon Processing, Sept. 2004, pp. 69-74)

Now we shall address formal details of the project approval scope. Following are the working assumptions:

  • The analyzer project engineer begins with a brief capital work order that includes an operative statement, such as, “Install analyzer on West Final Purification Tower to measure residual reactant.” Other information includes a desired project completion date, the purpose of the project (safety, environmental, economic expansion, etc.), and sufficient technical detail for the engineer to generate a few questions for the first user-client inquiry.
  • The management approval package must include a written scope, cost estimate (+/-10%), preliminary impact review (personnel and process safety, environmental and utility), red-lined (marked with additions, changes and demolitions) drawings, project schedule and analyzer, and associated instrument specifications.

We shall concentrate on the written scope, which probably has a standard format, but note that other documents frequently contain information needed to develop the project scope and, conversely, that the project scope will eventually be reflected directly or indirectly in the other documents.

Table I shows a typical project approval scope document structure. For simplicity, let us assume that the detailed estimate document generally follows the structure of the detailed scope, and that the latter does not include dollar amounts.


Typical Project Approval Scope of Work Document Structure

  1. Project Title and Number
  2. Project Purpose
  3. Brief Project Scope
  4. Brief Project Justification
  5. Detailed Scope
  6. Potential Construction Problems
  7. Potential Cost Problems
  8. List of Supporting Documents

Table 2 shows the detailed scope structure that would be included under Item 5 in Table I.


Typical Work Types Included in Detailed Scope

  • Architectural and landscaping 
  • Civil 
  • Foundations 
  • Structural and pipe racks 
  • Roadways and yards 
  • Railroads 
  • Waterways and navigation 
  • Below-ground piping, trenches, ditches and excavation 
  • Mechanical 
  • Unfired pressure vessels 
  • Fired pressure vessels 
  • Storage tanks 
  • Rotating equipment 
  • Above-ground piping 
  • Instrument and Electrical 
  • Field instruments (other than final control elements and pressure safety devices) 
  • Final control elements 
  • Pressure safety devices 
  • Local signal cabling (analog and discrete) 
  • Home-run signal cabling 
  • Rack-room wiring 
  • PLC and hardwired relay panels 
  • DCS 
  • Software 
  • Computers 
  • Voice and digital/protocol-based communications 
  • Motors 
  • Electrical below 480 Vac (including local wiring) 
  • Electrical above 480 Vac but below 13.8Kvac 
  • Electrical above 13.8KV 
  • Spare Parts 
  • Commissioning 
  • Construction Indirects 
  • Construction management and field supervision 
  • Equipment rentals 
  • Temporary changes 


  • Preliminary engineering
  • Detailed engineering
  • Startup
  • Repair and relocation
  • Dismantling, demolition, and disposal
  • Decontamination and remediation

Table II includes much detail that we don’t have space to discuss. Readers will be able to develop scenarios wherein any of these factors could influence—or be influenced by—a process analyzer project. It is highly unlikely that all would be included in a given project, but the wise reader should not be surprised if any one of them is included.

Look closely at the key items in Table II. An analyzer is a field instrument; therefore, the first item under Instrument and Electrical should be carefully worded to describe the proposed system. The words “analyzer system” are important to convey the idea that the project involves more than a single instrument and includes the analyzer or analytical sensor, a sample handling system (SHS) and additional equipment and devices. This document is probably not the appropriate one for these details, but it is important to plant the notion that analyzers tend to be more complex (and expensive!) than conventional field instruments.

As a field instrument, an analyzer system naturally requires local wiring, home-run signal cable, low-voltage power wiring, rack-room wiring and control room (DCS, PLC, etc.) work. These items constitute the probable minimum hardware scope for a process analyzer project.

Non-hardware capital items include commissioning, construction management and rental equipment. Among the expense items, startup is the minimum (in addition to engineering).

But the scope of most process analyzer projects goes beyond these “minimums.” An analyzer is a “field instrument,” which puts it in the same category as temperature, pressure, flow and level transmitters, all of which measure extensive properties. But an analyzer measures chemical composition, which is an “intensive property” of the manufacturing process at a given point, making it inherently more complicated than its conventional counterparts, and making  system project scopes longer and affecting more scope line items.

With an active client, the analyzer project engineer should not be alone in the effort to develop an acceptable detailed scope. Each project should have safety, environmental and utility reviews early in scope development and feasibility study. These reviews usually require a face-to-face meeting among at least some of the project team members and have a set format or form. These reviews often clarify, suggest or require the addition of many of the scope items. If allowed under the review procedure, these meetings are an excellent opportunity for the analyzer project engineer to ask explicitly about these scope items and listen to client concerns not previously raised.

Most line items in Table II will have direct labor and direct material costs, reflected on the estimate page of the project approval package. Table III is a list of typical red-lined drawings that would accompany the project approval scope and that would clarify and amplify the verbal content of the written scope for all members of the project team.


Typical Redlined Drawings and Sketches for Analyzer Project Scope Development


  • Piping and instrument drawing (P&ID)
  • Instrument loop sheet
  • Instrument location drawing

As Needed/Usually Helpful

  • Process flow drawing (PFD), may be called energy and material balance
  • Sample handling system (SHS) drawing or sketch
  • Analyzer system elevation drawing or sketch
  • Photos

The analyzer system project engineer may also wish to use drawings from other disciplines such as site plans and elevations, piping isometrics and vessel drawings to clarify scope.

  About the Author

Gary Nichols, PE, is principal control systems engineer with Jacobs Engineering Group and can be reached at [email protected].

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